THE  LIBRARY 

OF 

THE  UNIVERSITY 
OF  CALIFORNIA 

LOS  ANGELES 


The  RALPH  D.  REED  LIBRARY 

•O 

DEPARTMENT  OF  GEOLOGY 

UNIVERSITY  OF  CALIFORNIA 

LOS  ANGELES,  CALIF. 


THE 

A  B  C  OF  MINING 

A  Handbook  for  Prospectors 


TREATING  FULLY  OF  EXPLORATORY  AND  PREPARATORY  WORK  OF  THE  PHYSI 
PROPERTIES  OF  ORES,  FIELD  GEOLOGY,  TUB  OCCURRENCE  AND  Associ/ 
TIONS  OF  MINERALS,  METHODS  OF  CHEMICAL  ANALYSIS  AND  ASSAY, 
BLOW-PIPE  TESTS,  PROMISING  INDICATIONS,  AND  SIMPLB  METH- 
ODS OF  WORKING  VALUABLE  DEPOSITS,  TOGETHER  WITH 
CHAPTERS  ON  QUARTZ  AND  HYDRAULIC  MINING  AND 
ESPECIAL   DETAILED   INFORMATION  ON  PLACER 
MINING,  WITH  AN  ADDENDA  ON  CAMP  LIFE 
AND  MEDICAL  HINTS. 


BY 
CHARLES  A.  BRAMBLE,  D.  L.  S., 

Late  of  the  Editorial  Staff  of  "The  Engineering  and  Mining- 
Journal,"  and  formerly  a  Crown  Lands  and  Mineral 
Surveyor  for  the  Dominion  of  Canada. 


ILLUSTRATED. 


CHICAGO  AND  NEW  YORK  : 
RAND,  McNALLY  &  COMPANY, 


Copyright,  1898,  by  Rand,  McNally  &  Cc 


Geology 
Library 


B-734, 


PREFACE. 

Owing  to  recent  rich  discoveries  in  more  than  one 
mining  field,  hundreds  of  shrewd,  intelligent  men  with- 
out experience  in  prospecting  are  turning  their  atten- 
tion to  that  arduous  pursuit — to  such  this  book  is 
offered  as  a  safe  guide. 

A  complex  subject  has  been  treated  as  simply  as 
its  nature  permitted,  and  when  a  scientific  term  could 
not  be  avoided,  the  explanation  in  the  glossary  has 
been  offered. 

CHARLES  A.  BRAMBLE,  D.  L.  S. 


PREFACE  TO   SECOND   EDITION. 

A  steady  demand  for  this  work  has  shown  that 
it  fills  a  want,  and  serves- the  purpose  for  which  it 
was  written.  In  issuing  this  second  edition,  a  few 
compositors'  errors  that  had  crept  in,  owing  to  the 
author  being  in  a  very  remote  region  while  the 
book  was  going  through  the  press,  have  been  cor- 
rected, but  no  material  changes  in  the  text  were 
found  desirable. 

788819 


CONTENTS. 

THE  A  B  C   OF   MINING. 

PAGE 

CHAPTER  I  —  Prospecting, 7 

II  — How  to  Test  for  Minerals 38 

III  — Blow-Pipe  Tests 65 

IV  —  Economic  Ores  and  Minerals, 75 

V  — Mining 100 

VI  — Camp  Life 143 

VII  —  Surveying, 155 

VIII  — Floating  a  Company 161 

IX  — Medical  Hints,  .     t 165 

X  — Dynamite, 168 

XI  —  Atomic  Weights, 170 

XII  — Odds  and  Ends 172 

Glossary, 181 


ABC  OF  MINING. 


CHAPTER  I. 
PROSPECTING. 

Many  men  seem  to  think  that  should  their  destinies 
lead  them  into  parts  of  the  world  where  there  is  min- 
eral wealth  they  will  have  little  chance  of  discovering 
the  deposits  without  the  technical  education  of  a  min- 
ing engineer.  This  is  wrong.  The  fact  is  that  the 
sphere  of  the  prospector  does  not  cover  that  of  the 
engineer.  The  work  of  the  one  ends  where  that  of 
the  other  begins,  and  many  of  the  most  successful  dis- 
coverers of  metallic  wealth  have  been  entirely  ig- 
norant of  the  methods  by  which  a  great  mine  should  be 
opened,  developed,  and  worked. 

A  few  simple  tools  and  a  not  very  deep  knowledge 
of  assaying,  with  an  observant  eye  and  a  brain  quick 
to  deduce  inferences  from  what  that  eye  has  seen,  are 
the  most  valuable  assets  of  a  prospector.  In  time  he 
will  gain  experience,  and  experience  will  teach  him 
much  that  he  could  not  learn  in  any  college  nor  from 
any  book.  Each  mining  district  differs  from  every 
other,  and  it  has  been  found  that  certain  rules  which 
hold  good  in  one  region,  and  guide  the  seeker  after 
wealth  to  the  hidden  treasure  that  has  been  stored  up 
for  eons  of  time,  do  not  apply  in  another  region. 
7 


8  A.B  C   OF    MIXING 

To  show  what  may  be  done  with  imperfect,  impro- 
viM'd  apparatus,  an  Australian  assayer,  who  has  since 
become  famous,  started  up  country  in  his  youth  with 
the  following  meager  outfit:  A  cheap  pair  of  scales,  a 
piece  of  cheese  cloth,  a  tin  ring  i  1-2  inches  by  1-2 
inch,  a  small  brass  door-knob,  some  powdered  borax, 
some  carbonate  of  soda  and  argol,  a  few  pounds  of  lead 
lining  taken  from  a  tea  chest,  an  empty  jam  pot,  a 
short  steel  drill,  a  red  flower  pot.  With  this  modest 
collection  of  implements  he  made  forty  assays  of  gold 
ores  that  turned  out  to  be  correct  when  repeated  in 
a  laboratory. 

About  the  best  advice  that  can  be  given  to  a  man 
who  has  determined  to  go  to  some  out  of  the  way  re- 
gion where  there  is  a  possibility  of  his  discovering 
minerals  is  to  recommend  him  to  visit  the  nearest  mu- 
seum and  gain  an  acquaintance  with  the  common 
rocks.  Should  he  be  unable  to  do  this  he  had  better 
provide  himself  with  small,  inexpensive  specimens 
from  the  shop  of  some  dealer.  It  is  almost  impossible 
to  teach  a  beginner  to  distinguish  the  various  rocks 
by  any  amount  of  printed  instruction ;  the  only  way  to 
learn  to  recognize  them  is  to  handle  them  and  note 
carefully  their  color,  weight,  and  the  minerals  that  go 
to  make  them  up.  The  explorer  should  be  able  to 
recognize  at  a  glance,  or  at  any  rate  after  a  very  short 
inspection,  the  sedimentary  rocks,  such  as  sandstone 
and  limestone;  the  metamorphic  rocks,  that  is,  rocks 
that  haVe  been  altered  by  the  agency  of  great  sub- 
terranean heat  in  ages  long  past,  and  which  were 
probably  stratified  rocks  at  one  period,  such  as  granite 


PROSPECTING.  9 

and  gneiss,  and  the  truly  igneous  rocks — trap,  diabase, 
diorite,  etc.  He  must  know  also  that  mysterious  rock 
which  the  western  miner  calls  porphyry,  and  to  which 
is  ascribed  most  wonderful  virtues  in  the  way  of  ore 
attraction ;  while  dolerite  and  dolomite  must  be  to  him 
familiar  terms  and  substances.  This  sounds  easy 
rnotigh  but  the  student  will  find  that  a  good  deal  of 
hard  work  is  necessary  before  he  can  readily  recognize 
each  of  these  rocks. 

It  is  even  more  necessary  that  he  should  learn  the 
metals  thoroughly.  Each  one  differs  from  all  the  rest 
in  some  particular.  Often  this  difference  will  be  an 
obscure  one,  but  to  the  careful  investigator  the  recog- 
nition of  the  substance  will  be  in  the  end  certain.  They 
may  differ  in  weight,  in  color,  in  hardness,  in  a  dozen 
different  ways,  so  that  to  the  man  who  has  made  a 
study  of  this  subject  a  determination  is  always  possible. 

On  account  of  the  wonderful  discoveries  in  the 
Canadian  Northwest  and  in  Alaska,  the  eyes  of  thou- 
sands are  turned  towards  those  fields.  Wonderfully 
rich  placer  ground  has  already  been  found  and  there 
can  be  no  reason  to  doubt  that  very  much  larger  areas 
remain  unproved.  Where  this  gold  comes  from  is  an 
open  question;  geologists,  mineralogists  and  chemists, 
not  to  mention  mining  engineers  and  practical  pros- 
pectors, have  disputed  over  the  source  of  the  gold  al- 
ready found,  but  it  must  be  confessed  that  there  are 
almost  as  many  theories  as  there  are  disputants.  Could 
it  be  known  with  certainty  how  and  under  what  condi- 
tions the  gold  got  where  it  is  found,  the  problem  of 
seeking  for  it  might  be  made  easier.  Unfortunately 


10  ABC   OF    MINING. 

this  is  not  the  case,  and  all  prospecting  for  the  home 
of  the  precious  metal  is  more  or  less  a  groping  in  the 
dark.  We  do  know  that  the  heaviest  particles  of  gold 
do  not  travel  far  from  where  they  were  first  deposited, 
because  gold  is  so  enormously  heavy — its  specific 
gravity  being  about  nineteen  times  that  of  water — it 
seeks  the  bottom  of  the  stream  and  stays  there.  It  is 
not  an  invariable  rule  that  the  gold  increases  in  coarse- 
ness as  the  stream  is  ascended,  but  it  is  a  very  general 
one.  On  some  rivers  rich  and  poor  stretches  of  gold- 
bearing  gravel  succeed  one  another  as  the  explorer 
makes  his  way  up  or  down  stream.  This  is  difficult 
to  account  for,  but  in  many  cases  is  believed  to  be 
caused  by  the  modern  river  robbing  the  bed  of  some 
one  or  more  ancient  water-courses  whose  beds  crossed 
the  valley  of  the  present  stream.  This  may  or  may 
not  be  the  case.  We  only  know  that  the  miners  who 
found  coarse  gold  on  the  lower  regions  of  such  rivers 
as  the  Frazer  were  miserably  disappointed  when  they 
reached  stretches  near  the  source  and  found  nothing 
but  flour  gold.  This  same  feature  has  been  noticed  in 
some  of  the  Alaskan  rivers.  It  is  quite  within  the 
bounds  of  probability  that  no  very  rich  quartz  veins 
exist  in  Alaska.  It  does  not  follow  from  the  richness 
of  the  placers  that  the  gold  is  derived  from  very  rich 
quartz  lodes,  because  this  amount  of  gold  may  really 
represent  the  product  of  a  vast  amount  of  rock  that 
has  been  ground  to  powder  and  washed  away  in  the 
course  of  ages.  The  gold  would  not  travel  far,  and 
the  deposits  being  unearthed  to-day  have  been  accu- 
mulating in  these  northern  streams  since  the  world 


PROSPECTING.  II 

was  young;  water-courses  are  nature's  ground  sluices. 
It  is  possible  that  one  stream  has  cut  through  the 
drainage  of  another.  Sometimes  this  has  impover- 
ished the  first  and  enriched  the  second,  while  in  other 
cases  the  reverse  has  obtained.  Upheavals  have  formed 
faults*  and  fractured  the  strata,  and  the  gold  may  have 
been  deposited  by  solution  in  these  fractures.  Often 
the  soil  will  have  been  washed  away  from  near  the  top 
of  the  mountain,  so  that  layers  of  stratified  rock  are 
seen  to  be  duplicated  on  each  side  while  they  are  cov- 
ered at  the  summit.  The  prospector  keeps  his  eye 
open  as  he  goes  along  and  notes  carefully  the  charac- 
ter of  the  fragments  of  rock  he  finds  in  the  streams. 
Quartz,  diorite,  diabase,  and  porphyry  pebbles  are 
grounds  for  expecting  a  profitable  result,  but  of  course 
there  is  no  certainty  of  such  a  happy  issue.  As  soon 
as  the  district  begins  to  be  fairly  well  known  certain 
discoveries  are  made  that  invariably  render  prospect- 
ing easier.  Local  peculiarities  are  noted ;  certain  char- 
acters are  found  to  be  common  to  the  ore-bearing'bod- 
ies  or  deposits;  the  lines  of  deposits  become  known, 
and  a  good  deal  of  light  is  then  shed  upon  a  very  diffi- 
cult problem.  As  a  rule,  when  the  fragments  of 
quartz,  pyrite,  chalcopyrite,  or  galena  are  rough,  they 
have  not  traveled  far,  and  the  lode  from  which  they 
have  been  derived  should  be  close  at  hand.  Water 
and  attrition  soon  round  these  minerals  on  their  sharp 
edges,  and  thus  showr  that  they  have  come  from  some 
little  distance. 


*Dislocation   of  the  strata. 


12  ABC   OF    MINING. 

In  some  countries,  especially  where  vegetation  is 
scanty,  the  outcrop  of  a  body  of  mineral  may  be  traced 
by  a  difference  in  the  vegetation.  In  South  Africa  a 
chain  of  pools  usually  follows  the  course  of  a  line  fault, 
which  in  its  turn  marks  where  an  intrusive  lode  carry- 
ing mineral  separates  two  different  formations.  As  a 
rule,  any  heavy  mineral  is  worth  investigating.  Even 
in  remote  regions  silver,  mercury,  tin,  nickel,  plati- 
num, copper,  and  several  other  metals  are  worth  pay- 
ing attention  to.  If  they  are  too  far  away  from  the 
railroad  or  the  steamboat  to-day  they  may  not  be  so 
next  year,,  for  civilization  advances  with  giant  stride 
in  these  days  and  never  faster  than  when  transporta- 
tion companies  are  reaching  forth  to  some  newly  dis- 
covered mineral  field. 

One  of  the  greatest  drawbacks  to  prospecting  in  the 
North  is  the  dense  growths  of  moss  and  forest  that 
cover  the  ground.  In  most  of  the  Western  states,  in 
South  Africa,  and  in  Australia  this  drawback  does  not 
exist  and  prospecting  was  by  that  much  the  easier. 
However,  as  a  compensation,  there  is  abundant  water 
in  Alaska  and  the  Northwest,  while  it  was  and  is  almost 
entirely  absent  in  several  other  regions  that  possess  im- 
mense bodies  of  ore  which  are  not  available  for  this 
very  reason. 

Quartz  has  been  called  the  mother  of  gold,  and  cer- 
tainly quartz  and  gold  are  inseparably  connected  to- 
day. As  to  where  gold  may  be  found  the  best  reply 
that  can  be  given  is  in  the  words  of  the  old  miner,  who, 
when  asked  that  question,  said:  "Where  it  be's;  there 
it  be's,"  and  then  added,  "and  there  ben't  I." 


PROSPECTING.  13 

Although  most  prospectors  travel  alone  from  sheer 
necessity,  there  can  be  no  doubt  that  three  or  four  men 
forming  a  party  and  working  together  have  the  ad- 
vantage. They  can  do  their  work  cheaper,  more  thor- 
oughly, and  more  surely.  By  co-operating  they  may 
carry  a  more  complete  outfit.  Should  any  accident 
happen  help  is  at  hand,  whereas  the  solitary  wanderer 
often  dies  as  the  result  of  some  accident  that  would 
have  been  trivial  had  he  had  a  companion.  Three  or 
four  claims  may  be  worked  in  conjunction  with  one 
another  at  far  less  proportionate  expense  than  a  single 
one  could. 

Nature's  preparation  for  the  reception  of  great  ore 
deposits  is  somewhat  as  follows:  The  crust  of  the 
earth  is  prepared  for  the  reception  of  the  metals  by 
great  outbursts  of  igneous  or  melted  rocks ;  the  metals 
themselves  being  carried  in  suspension  in  the  heated 
water  that  everywhere  traverses  the  strata.  These 
metals  are  deposited  in  the  veins  as  soon  as  the  waters 
begin  to  cool,  and  the  pressure  to  which  they  were  sub- 
jected from  deep  down  in  the  earth's  crust  is  removed. 
A  great  mineral  country  is  usually  marked  by  the  out- 
crops of  the  veins  being  persistent  in  their  courses  and 
traceable  for  many  miles,  though  very  probably  many 
breaks  may  occur  in  these  outcrops.  The  rocks  asso- 
ciated with  great  ore  bodies  are  lime,  porphyry,  gran- 
ite, shales,  slates,  quartzites,  and  diabase.  Fragments 
of  mineral  and  gangue,  known  to  the  miners  as  float, 
may  be  littered  over  the  hills  and  encumber  the  courses 
of  the  stream.  A  central  line  of  eruption  may  often 
be  traced  by  masses  of  altered  rock,  and  beds  of  lava 


14  ABC   OF   MINING. 

or  other  volcanic  products.  We  find  the  granite  has 
been  melted  and  the  limestone  has  acquired  magnesia, 
and  thus  become  dolomatized. 

Whenever  a  heavy  deposit  of  pyrites,  or  mundic,  is 
found  mineral  probably  exists  below.  The  cubes  of 
pyrite  are  not  always  valueless,  they  may  contain  gold 
in  addition  to  the  iron  and  sulphur.  When  the  pyrites 
decay  under  the  influence  of  the  weather,  and  leave  the 
quartz  honeycombed,  these  cavities  often  contain  con- 
centrated gold;  for  which  reason  you  often  get  a 
higher  assay  from  the  surface  than  from  any  point 
lower  down  in  the  vein.  In  sinking  the  shaft  soon 
gets  below  this  altered  quartz  and  the  ores  are  then 
combined  with  sulphur.  They  have  become  sulphides, 
and  are  harder  to  treat.  The  prospector  should  there- 
fore act  very  cautiously  when  trying  to  develop  a 
mine  with  a  small  capital  behind  him;  because,  al- 
though the  first  ore  may  be  adapted  for  stamping,  he 
may  find,  before  he  has  gone  down  fifty  feet,  that  it 
can  only  be  treated  in  a  smelter,  and  that  all  the  money 
he  has  put  into  crushing  apparatus  is  wasted. 

Without  the  prospector  there  would  be  no  mining 
and  the  world  would  yet  be  in  the  stone  age.  He  is  not 
appreciated  at  anything  like  his  real  worth.  He  re- 
quires ability  and  experience,  push  and  perseverance. 
Prospecting  is  a  search  for  valuable  minerals.  He 
may  not  be  very  deeply  learned  in  either  geology  or 
mineralogy,  but  he  must  have  a  keen  eye  and  good 
natural  powers  of  observation. 

There  are  some  sixty  or  seventy  elements  in  the 
world,  and  the  most  common  is  oxygen.  Nearly  all 


PROSPECTING.  15 

the  coloring  matter  of  rocks  comes  from  iron.  Wind, 
frost,  rain,  snow,  and  heat,  cause  a  crumbling  of  the 
different  rocks,  and  running  water  wears  them  away, 
and  carries  off  and  distributes  the  particles.  By  this 
agency,  and  by  floating  ice,  they  are  often  removed  to 
long  distances.  The  action  of  internal  heat  renews 
the  deposits  of  mineral  by  eruption,  or  by  hot  springs, 
but  this  means  of  renewal  was  much  more  powerful 
in  the  past  than  it  is  now. 

Organic  matter  found  in  the  crust  of  the  earth  was 
derived  from  animals  or  vegetables.  Coal  is  a  legacy 
from  forests  that  flourished  ages  ago,  while  petroleum 
is  all  that  remains  of  vast  schools  of  fishes  that 
swarmed  in  Devonian  seas. 

Stratified  rocks  are  either  sand,  clay,  or  calcareous, 
which  means  lime-bearing.  In  their  natural  position 
they  were  horizontal,  but  owing  to  subsequent  vol- 
canic action  they  are,  in  some  localities,  tilted  at  all 
conceivable  angles.  The  eruptive  rocks  have  burst 
through  them  in  places,  changed  their  character,  di- 
vided them  by  intrusive  masses,  and  generally  enriched 
them  with  mineral  deposits. 

Everything  now  known  points  to  the  theory  that 
the  contents  of  veins  were  deposited  in  the  lodes  by 
infiltration.  In  a  few  instances  famous  mines  have  no 
veins,  but  are  literally  hills  of  mineral;  they  are  then 
of  low  grade,  but  much  more  remunerative  than  aver- 
age high  grade  mines,  owing  the  vast  quantity  of  ore, 
and  the  ease  with  which  it  can  be  mined.  The  famous 
Treadwell  mine,  on  Douglas  Island,  Alaska,  has  ore 
that  is  worth  less  than  four  dollars  a  ton,  but  it  is  quar- 


16  ABC   OF    MINING. 

ried,  and  640  stamps  work  day  and  night.  There  is 
about  a  dollar  a  ton  profit,  and  hundreds  of  thousands 
of  tons  are  treated  annually.  The  tin  mine  known  as 
Mount  Bischoff,  in  Tasmania,  and  the  Burra  copper 
mim-  in  Australia  are  other  instances.  Each  of  these 
deposits  was  found  as  an  outcropping  on  the  bare  top 
of  a  low  hill,  and  none  of  them  has  walls. 

A  fault  may  throw  the  vein  up  or  down,  and  a  good 
deal  of  exploration  may  have  to  be  done  before  it  is 
recovered. 

A  lenticular  vein  consists  of  a  series  of  double  pointed 
ore  bodies  like  lenses  which  may  be  strung  out,  over- 
lapping, or  not. 

The  outcrop  of  a  vein  is  never  the  same  as  its  strike, 
except  on  a  level  surface. 

A  stringer  of  ore  branching  off  from  the  main  vein 
is  known  as  a  chute,  shoot,  or  chimney. 

In  developing  a  ledge  or  lode,  first  find  out  what 
the  ore  is.  Gold  is  shown  in  the  mortar,  especially 
after  roasting.  Silver  may  be  recognized  at  sight,  or 
by  assay  tests,  or  blow  pipe ;  copper,  by  its  vivid  colors. 
— green  or  blue  for  carbonate  and  red  for  oxide  or 
metallic  copper.  The  ore  often  differs  in  various  parts 
of  the  vein.  Explore  your  lode  along  the  surface. 
across,  and  down  its  dip.  When  you  find  it  continuous 
it  will  be  time  enough  to  think  of  a  vertical  shaft.  The 
top  of  a  shaft  must  be  timbered  with  logs,  so  as  to  give 
sufficient  fall  to  get  rid  of  the  mineral  when  it  is 
hoisted. 

The  first  thing  the  prospector  has  to  consider  is  his 
outfit.  The  more  complete  this  is  the  better,  but  nine- 


PROSPECTING.  17 

ty-nine  times  out  of  a  hundred  the  difficulties  of  trans- 
portation in  a  wild  region  are  so  enormous  that  he  will 
have  to  do  without  a  great  many  things  that  he  would 
like  to  have.  He  must  endeavor  to  make  up  for  the 
lack  of  tools  by  ingenuity ;  then  he  may  get  along  fairly 
well.  A  pan,  he  must  have.  In  this  he  will  wash  care- 
fully all  his  samples.  Then,  a  flask  of  quicksilver  is 
more  precious  to  him  even  than  gold;  for,  having  it, 
he  can  resort  to  pan-amalgamation,  which  will  save  the 
precious  metal  even  when  it  is  in  minute  particles. 

This  process  may  be  described  as  follows :  A  pound 
or  two  of  the  ore  in  powder  is  placed  in  the  pan  and 
water  is  added  until  the  mass  becomes  a  thin  pulp. 
One  ounce  of  quicksilver  and  a  small  piece  of  that 
deadly  poison,  known  to  the  chemist  as  cyanide  of  pot- 
ash, and  as  prussic  acid  to  the  ordinary  man,  should  be 
added,  and  the  mass  should  be  stirred  thoroughly,  for 
two  hours  if  you  can  stand  it.  Then  turn  in  water  and 
wash  off  the  dirt  and  the  amalgam  will  be  found  in 
the  bottom  of  the  pan.  This  you  must  collect  very 
carefully.  You  should  have  a  square  piece  of  chamois 
skin  or  a  piece  of  strong  white  cotton  cloth.  In  either 
case  the  amalgam  is  put  in  the  center  of  this  square 
and  the  cloth  twisted  until  all  the  superfluous  quick- 
silver is  pressed  out  and  your  amalgam  remains  nearly 
free  from  mercury.  This  amalgam  placed  on  a  shovel 
and  held  over  a  brisk  fire  will  soon  show  the  yellow 
color  of  gold.  If  you  have  no  mould  you  may  make 
one  of  clay,  put  your  gold  therein  with  a  little  borax, 
and  very  soon,  the  fire  being  hot  enough,  you  will  have 
a  tiny  ingot  of  the  precious  metal.  But  most  pros- 


i8  ABC  OF   MINING. 

pectors  are  satisfied  when  they  have  obtained  their 
sponge  gold,  and  do  not  carry  their  operations  further 
in  these  rough  and  ready  tests. 

The  prospector  of  to-day  is  often  a  very  different 
man  from  his  predecessor  of  a  generation  ago.  The 
old  gold  hunter  used  to  sally  forth  armed  with  a  pick, 
shovel  and  pan,  and  usually  a  very  little  grub.  In 
his  stead  men  are  now  taking  the  field  who  have  had 
the  benefits  of  a  thorough  education,  both  practical 
and  theoretical,  and  provided  with  all  the  equipment 
necessary  for  their  work.  Some  of  these  men  carry 
an  outfit  somewhat  as  follows :  An  iron  mortar  hold- 
ing half  a  gallon,  together  with  a  pestle  a  rough  scale 
for  pulp,  a  more  delicate  one  showing  troy  grains  and 
pennyweights,  a  4O-mesh  sieve,  a  burro  furnace  and 
muffle,  one  cupel  mould,  a  couple  of  dozen  scorifiers, 
tongs  to  handle  the  cupel  and  scorifiers,  two  anneal- 
ing cups,  a  spirit  lamp,  a  dozen  test  tubes,  a  pouring 
mould,  five  or  six  pounds  of  borax  and  about  as  much 
carbonate  of  soda,  five  pounds  of  bone  ash,  ditto  of 
granulated  lead,  a  pint  of  nitric  acid,  ditto  of  hydro- 
chloric acid,  ditto  sulphuric  acid,  ditto  of  ammonia, 
twice  as  much  alcohol  and  two  pounds  or  so  of  gran- 
ulated zinc. 

As  a  blow  pipe  outfit  he  will  take  a  blow  pipe,  spirit 
lamp,  nitrate  of  cobalt  in  solution,  cyanide  of  potash, 
yellow  prussiate  of  potash,  red  prussiate  of  potash,  a 
sheet  or  two  of  filtering  paper  and  a  couple  of  three- 
inch  glass  filters.  With  this  outfit  he  can  determine 
any  mineral  he  may  come  across. 

By  patience  and  observation  the  man  who  starts  out 


PROSPECTING.  19 

to  take1  up  prospecting  as  a  road  to  fortune  may  easily 
master  the  rudiments  of  his  business.  It  will  not  take 
him  long  to  become  familiar  with  the  commoner  rocks, 
and  the  more  valuable  ores.  His  own  rough  tests  in 
the  field  must  be  confirmed  by  competent  assayers  up- 
on his  return  to  civilization,  and  in  this  matter  he 
should  be  very  guarded.  The  most  reliable  assays  are 
made  either  at  the  different  government  assay  offices 
or  by  some  of  the  large  metallurgical  works  whose 
reputation  is  world  wide.  Prospecting  is  hard  work, 
but  the  life  is  healthy  and  full  of  excitement,  only  the 
explorer  should  have  courage,  hope,  and  good  temper, 
for  each  and  every  one  will  be  as  necessary  in  his 
chosen  vocation  as  his  pan  and  pick. 

When  alluvial  or  placer  gold  has  been  found  it  is 
reasonable  to  suppose  that  the  vein  from  which  it  was 
derived  may  also  reward  diligent  search,  for  it  is  un- 
doubtedly true  that  most  placer  gold  has  come  from 
quartz  veins.  This,  however,  is  believed  not  to  be  in- 
variably the  case,  a  recent  school  of  mineralogists  con- 
tending that  pure  masses  of  alluvial  gold  have  been 
formed  from  the  accretion  or  growth  of  the  gold  de- 
posited from  certain  gold  salts.  This  is  in  any  case 
probably  exceptional,  and  the  prospector  who  finds 
gold  in  gravel  should  seek  in  the  adjacent  country  for 
the  quartz  lodes  from  which  it  came. 

Important  deposits  may  be  expected  at  or  about  the 
line  of  unconformability  where  slates,  shales,  quartz- 
ites,  sandstones,  limestones,  schists  and  other  sedi- 
mentary deposits  are  pierced  by  intrusive  masses  of 
igneous  rocks. 


20  ABC   OF   MINING. 

Veins  filling  the  cracks  that  once  existed  between 
two  differing  rocks  are  known  as  contact  veins.  Such 
veins  are  often  very  rich.  Curiously  enough  large 
masses  of  true  igneous  rock  rarely  contain  valuable  de- 
posits of  mineral,  but  where  such  intrusive  masses  cut 
dikes  or  walls  of  porphyry,  or  diorite,  the  region  is 
worthy  of  careful  investigation. 


POCKET    LENS. 

In  an  open  country  the  prospector  should  keep  to 
the  hill  tops  if  on  the  lookout  for  veins,  as  the  outcrops 
show  more  distinctly  on  the  bare  ridges,  but  alluvial 
deposits  are  only  found  in  valleys  and  along  the  bor- 
ders of  streams.  In  any  case,  much  of  the  northern 
part  of  this  continent  can  only  be  prospected  by  fol- 
lowing the  streams,  on  account  of  the  dense  growth 
of  forest  with  which  the  soil  is  covered.  The  true  line 


PROSPECTING.  21 

of  strike  of  a  vein  can  be  determined  only  on  a  level 
stretch.  The  line  of  strike  and  the  line  of  dip  are  al- 
ways at  right  angles  to  one  another;  the  outcrop  may 
follow  the  strike  or  it  may  not. 

A  pick,  shovel,  and  pan,  are  absolutely  necessary  to 
a  prospector's  proper  equipment.  A  good  pocket 
lens,  cheesecloth  screen,  and  small  iron  pestle  and 
mortar  are  often  useful.  The  pan  is  the  most  essential 
part  of  the  outfit,  and  is  always  bright  from  use. 

The  regular  gold  miner's  pan  is  13!  inches  in  diam- 
eter across  the  top,  10  inches  across  the  bottom  and 
2|  inches  deep.  The  best  are  made  of  sheet  iron  and 
have  a  joint  around  the  bottom  rim  which  is  of  some 
assistance  in  retaining  the  spangles  of  gold. 

A  more  primitive  instrument  than  the  pan  is  the 
batea.  This  requires  more  skill  than  the  pan,  and  is 
much  in  favor  with  South  American  miners.  It  is 
made  of  hard  wood,  20  inches  in  diameter,  2,\  inches 
deep  in  the  center,  inside  measurement,  and  sloping 
gradually  to  nothing  at  the  sides. 

The  horn  spoon  has  been  handed  on  from  antiquity. 
It  is  made  from  a  black  ox  horn,  at  least  a  black  one 
is  the  best  as  it  shows  the  gold  better;  it  is  eight  to 
ten  inches  long  by  three  inches  wide,  cut  off  obliquely. 

When  gold  is  suspected  in  quartz,  but  there  is  vis- 
ible to  the  naked  eye  more  or  less  iron,  copper,  and 
other  base  metals,  it  is  well  to  crush  the  quartz  into 
coarse  fragments.  Roast  on  a  shovel  or  other  con- 
venient tool  over  a  hot  fire,  and  finally  pulverize  in 
the  mortar.  If  panned  it  will  now  reveal  much  of  its 
gold,  while,  had  these  measures  not  been  taken,  the 


22  A  HC    OF    MIXING. 

sample  might  have  given  negative  results  and  been 
declared  valueless. 

After  pulverizing,  the  ore  should  be  passed  through 
the  cheese  cloth  screen  before  panning.  If  the  approx- 
imate value  of  the  ore  is  sought,  the  sample  must  be 
dried  and  weighed  before  crushing;  and  the  resulting 
gold  weighed.  Thus: 

Sample  is  to  2,000  Ibs.  as  gold  found  is  to  Ans. 

About  13  cubic  feet  of  quartz  weigh  a  ton  before  be- 
ing disturbed;  When  broken  to  medium  sized  lumps 
20  cubic  feet  may  be  taken  as  representing  a  ton.  Al- 
though experience  teaches  the  miner  to  estimate  very 
closely  the  value  of  his  sample,  it  is  better  for  the  tyro 
to  have  a  small  pair  of  scales  with  grain  weights.  A 
grain  of  gold,  if  tolerably  pure,  is  equal  to  four  cents. 
Above  all  things  avoid  the  too  common  error  of  pan- 
ning the  pick  of  the  rock,  as  a  false  estimate  is  bound 
to  follow  and  only  too  probably  eventual  loss. 

A  yard  of  gravel  before  being  dug  makes  one  and 
a  half  yards  afterwards.  A  pan  of  dirt  is  usually  about 
20  pounds,  although  it  is  not  well  to  fill  quite  full  in 
actual  work. 

Many  a  valuable  mine  has  been  found  by  following 
up  "float"  ore.  Float  is  detached  fragments  of  the 
vein  or  gangue,  and  it  becomes  more  and  more  abun- 
dant as  the  lode  is  approached  until  it  finally  ceases 
abruptly.  This  indicates  that  the  vein  has  been 
reached  or  passed,  and  a  trench  dug  throughout  the 
alluvial  soil  at  right  angles  to  the  assumed  line  of  the 
vein  will  probably  reveal  it.  The  float  and  mineral  of 
course  drift  down  hill;  if  the  side  of  the  mountain  be 


PROSPECTING.  23 

saddle-shaped  the  float  will  spread  out  like  a  fan  as  it 
washes  down,  but  if  concave  the  force  of  gravity  will 
concentrate  it  within  a  narrow  space  in  the  ravine. 
Float  found  at  the  foot  of  a  hill  has  come,  as  a  rule, 
from  that  hill.  The  nearer  the  vein  the  less  worn  will 
be  the  edges  of  the  float  and  mineral.  The  gangue  or 
vein-rock  in  Which  the  metal  is  found  may  be  calcite 
or  calc  spar,  fluor  spar,  heavy  spar  or  baryta,  or  quartz. 
Gold  is  almost  always  found  in  this  last  matrix.  The 
upper  parts  of  most  quartz  lodes  are  usually  oxidized, 
that  is  to  say,  the  atmosphere  has  acted  upon  the  iron 
pyrites,  freeing  the  sulphur  and  staining  the  quartz 
yellow,  red,  or  brown,  by  oxide  of  iron.  This  is 
known  as  "gossan"  or  the  "iron  hat."  Such  quartz  is 
frequently  honeycombed  and  rotten.  Below  the  water 
level  these  veins  run  to  sulphides  in  which  decomposi- 
tion has  not  set  in,  and  the  gold  contained  in  the  quartz 
is  no  longer  "free  milling,"  i.  e.  will  not  give  up  its 
gold  to  mercury  without  a  preliminary  treatment. 

Whenever  the  explorer  comes  across  a  mass  of 
gossan  he  should  sink  a  trial  shaft  to  the  vein,  as  it  is 
almost  certain  that  below  the  oxidized  sulphides  a  body 
of  mineral  exists  likely  to  encourage  mining  opera- 
tions. 

Native  gold  is  malleable,  will  flatten  out  under  the 
hammer,  and  a  steel  knife  will  cut  it  with  ease.  It 
almost  invariably  contains  silver,  sometimes  to  the  ex- 
tent of  one-fifth.  A  little  practice  will  enable  the  pros- 
pector to  recognize  it,  for  there  is  but  one  king  metal. 
Much  gold  is  derived  from  copper  and  iron  pyrites, 


24  ABC   OF    MINING. 

and  silver  and  lead  ores  are  a  very  large  source  of 
supply. 

Gold  is  found  in  gravel  of  every  variety,  from  finest 
pipe-clay  to  boulders  weighing  tons.  Sometimes  vol- 
canic eruptions  have  covered  these  deposits  since  the 
ancient  rivers  laid  them  down,  and  in  many  cases  their 
courses  do  not  in  the  least  agree  with  the  valleys  of 
the  shrunken  streams  that  have  replaced  them. 

Gold  may  be  distributed  through  the  whole  thick- 
ness of  a  bed,  but  ninety-nine  times  out  of  a  hundred 
the  richest  layer  of  gravel  is  just  above  the  bed  rock 
upon  which  all  the  gravel  rests.  Gold  may  even  be 
found  among  the  grass  roots',  especially  in  dry  locali- 
ties where  there  has  been  little  water  to  carry  it  down- 
ward. When  the  bed  rock  consists  of  upturned  slates 
the  gold  frequently  penetrates  it  for  some  little  distance. 

Sand  is  nearly  always  poorer  than  gravel. 

The  experience  of  miners  in  the  Victoria  gold  fields 
is  that  gold  is  always  found  on  the  bars  £>r  points,  and 
not  in  the  deep  pools  and  bends. 

The  great  difficulty  with  which  any  but  the  very 
finest  particles  of  gold  can  be  moved  by  water  accounts 
for  the  value  of  the  deposits  depending  largely  upon 
the  local  rocks.  It  is  very  fortunate  that  gold's  specific 
gravity  is  so  great,  for  were  it  less  its  recovery  would 
be  much  more  difficult.  The  sluices  and  other  appa- 
ratus of  the  miner  are  really  nothing  but  the  operations 
of  nature  imitated  on  a  much  smaller  scale.  There  is 
one  thing,  however,  time,  that  nature  can  afford  to 
expend  in  prodigious  periods,  while  man  must  not 
waste  a  single  minute. 


PROSPECTING.  25 

It  not  being  possible  to  point  out  where  the  ancient 
river  bed's  lie,  smothered  as  they  are  by  hundreds  of 
feet  of  overlying  drift,  lava,  and  other  later  deposits, 
the  only  feasible  plan  is  a  series  of  boring  with  the  dia- 
mond drill. 

When  gold  has  been  discovered  the  finder  must  act 
with  the  greatest  prudence,  for  even  gold  may  be 
bought  too  dear.  The  surest  test  is  a  mill  run,  that  is 
passing  10  to  50  tons  through  all  the  operations  of 
crushing,  milling,  roasting,  amalgamating,  etc.,  and 
so  ascertaining  what  returns  are  likely  to  be  obtainable 
when  the  deposit  is  worked  on  a  commercial  scale. 
True  sampling  is  necessary.  All  parts  of  the  vein 
should  be  included,  and  the  lode  cross-cut  by  galleries 
in  more  than  one  spot.  It  is  the  very  great  necessity 
of  these  expensive  preparatory  explorations  that  has 
given  rise  to  the  saying,  "Quartz  mining  is  for  rich 
men." 

Many  gold  mines  have  been  abandoned  as  unprofit- 
able that  could  have  been  mined  at  a  profit  had  their 
owners  been  wealthy  and  enterprising  enough  to  do 
a  great  deal  of  expensive  prospecting  by  diamond  drill, 
cross  cuts,  drifts  and  rises.  In  one  instance  that  came 
to  the  writer's  knowledge  a  clever  mining  engineer 
cleared  nearly  $200,000  profit  by  leasing  for  a  term  of 
years  a  gold  mine  that  was  supposed  to  be  exhausted. 
A  drill  hole  sunk  less  than  50  feet  below  the  old  work- 
ings revealed  a  pocket  of  ore  in  the  vein,  and  paying 
quartz  was  found  for  many  hundred  feet  below. 

With  the  improvements  in  electricity  made  recently 
a  cheap  power  has  been  provided  that  will  permit  many 


26  ABC   OF    MINING. 

mines  to  be  reopened.  The  saving  in  working  ex- 
penses effected  by  introducing  electricity  is  often  very 
large;  after  the  plant  is  once  installed  the  cost  is  almost 
nil  where  turbines  can  be  employed  to  furnish  the 
power  to  the  generators.  Machinery  capable  of  deliv- 
ering power  at  a  distance  of  several  miles  from  the 
plant,  may  be  operated  at  very  reasonable  cost  as  com- 
pared to  that  of  other  prime  movers. 

Discoveries  of  many  deposits  that  have  in  time  been 
successfully  mined  were  the  result  of  chance.  No  skill 
guided  the  finder;  he  merely  stumbled  upon  his  luck 
just  as  the  wayfarer  once  in  a  while  hits  his  toe  against 
a  well-filled  pocketbook.  For  instance,  a  South  Aus- 
tralian squatter  picked  up  a  piece  of  copper  ore  that  a 
wombat  had  thrown  out  of  his  burrow,  and  the  result 
was  the  discovery  of  the  great  Wallaroo  lode.  The 
first  diamond  from  South  Africa  was  picked  up  by  an 
ignorant  bush  boy  and  kept  with  a  lot  of  worthless 
pebbles  in  the  private  collection  of  the  boy's  master; 
no  suspicion  existed  of  its  value  until  a  passing  trader 
had  carried  it  away  and  obtained  $2,500  for  it  in  Cape- 
town. Gold  was  first  discovered  in  California  in  1848 
by  the  superintendent  of  a  sawmill  who  saw  it  glisten- 
ing in  the  flume.  Similarly  gold  was  discovered  in  both 
Australia  and  Brazil  by  the  purest  chance.  Had  not  a 
tree  been  uprooted  by  the  wind  the  vast  deposits  of 
soft  hematite  iron  ore  in  the  Biwabic  iron  mines  of  the 
Mesabi  range,  Minnesota,  might  have  remained  un- 
known for  many  a  long  year  to  come.  In  the  desolate 
region  to  the  northward  of  Lake  Huron  great  stores  of 
nickel  ore  exist.  These  mines,  which  may  some  day 


PROSPECTING.  27 

regulate  the  price  of  the  metal  all  the  world  over,  were 
exposed  in  a  railway  cutting;  no  one  dreamed  of  their 
existence.  The  Redington  quicksilver  mine  in  Cali- 
fornia was  discovered  by  some  roadmakers.  Tradi- 
tion relates  that  the  enormously  rich  silver  mines  of 
Potosi,  in  Bolivia,  were  discovered  by  the  accidental 
uprooting  of  a  bush  having  spangles  of  silver  ore  at- 
tached to  its  roots.  This  was  in  1538,  and  two  hun- 
dred years  later  a  similar  streak  of  luck  revealed  the 
wealth  of  the  Catorce  district  of  Mexico,  from  which 
in  thirty  years,  ore  to  the  value  of  $35,000,000  was 
taken. 

Moreover,  the  search  for  one  mineral  often  leads  to 
the  discovery  of  another.  The  Comstock  lode  was 
first  worked  for  gold,  and  the  miners  threw  away  the 
black  sulphide  of  silver  worth  $3,000  to  the  ton.  The 
Broken  Hill  mine  in  Australia  was  claimed  as  a  tin 
deposit  by  its  finder;  it  is  now  the  greatest  silver  pro- 
ducer in  Australasia.  Such  instances  could  be  multi- 
plied almost  indefinitely,  chance  entering  into  a  ma- 
jority of  mineral  discoveries.  On  the  other  hand,  it 
has  happened,  not  infrequently,  that  purely  scientific 
deductions  and  calculations  have  brought  to  light 
stores  of  mineral  wealth. 

Certain  minerals  are  likely  to  be  found  associated. 
Cassiterite  goes  with  boron  and  tourmaline,  topaz, 
fluor  spar  and  lithia-mica;  all  containing  fluorine.  It 
is  also  found  with  wolfram,  chlorite  and  arsenical  py- 
rites. Magnetite  is  often  accompanied  by  rocks  con- 
taining garnet,  epidote  and  hornblende.  Zinc  blend 
and  galena  may  occupy  the  same  vein,  which  is  likely 


28  ABC   OF    MINING. 

to  be  of  baryta  or  heavy  spar.  Much  galena  carries 
silver.  Gold  is  associated  with  many  metallic  sul- 
phides such  as  iron,  magnetic,  and  copper  pyrites,  mis- 
pickel,  galena,  blend,  stibnite  and  tetrahedrite.  Gyp- 
sum accompanies  salt. 

Surface  indications  may  be  described  as:  Form  of 
ground,  color,  outcrop,  decomposed  and  detached  min- 
eral, mineral  deposits  from  springs,  altered  or  peculiar 
vegetation  and  other  similar  guides.  A  hard  quartz 
outcrop  often  stands  up  like  a  wall  and  is  traceable  for 
miles.  The  Rainbow  silver  bearing  lode  of  Butte, 
Montana,  stood  20  feet  above  the  surface.  Soft  min- 
erals, such  as  clay,  are  cut  into  and  sunk  below  the 
surrounding  level.  Deposits  of  Kaolin  or  China  clay 
are  usually  so  found. 

Any  special  bright  coloration  of  the  rocks  of  a  dis- 
trict merits  investigation.  Copper  gives  green,  blue, 
and  red  stains ;  iron,  red  or  brown ;  manganese,  black ; 
lead,  green,  yellow  or  white;  cobalt,  pink;  cinnabar  or 
quicksilver,  vermilion.  The  nickel  deposits  of  New 
Caledonia  were  made  known  to  the  world  by  the  ex- 
plorer Gamier  in  1863,  his  curiosity  having  been 
aroused  by  the  delicate  green  coating  given  the  rocks 
by  an  ore  containing  water,  quartz,  nickel  and  mag- 
nesium. 

Hard  beds  of  shale  decompose  on  the  surface  into 
soft  clay,  and  a  still  more  noticeable  change  is  the  con- 
version of  ores  containing  sulphur  into  oxides.  This 
chemical  change  causes  the  gossan  or  "iron  hat,"  for 
which  token  of  underlying  wealth  the  prospector 
should  be  eternally  watchful.  This  alteration  may  ex- 


PROSPECTING.  29 

tend  downward  four  or  five  hundred  feet  from  the  sur- 
face, but  in  such  cases  the  true  weathering  has  ceased 
long  before  the  limit  of  discoloration  is  reached,  and 
the  change  of  substance  is  due  to  the  filtering  of  sur- 
face waters  through  the  vein. 

Gossan  varies  greatly  in  its  nature.  Galena  be- 
comes anglesite,  cerussite,  pyromorphite  and  mimetite. 
Copper  pyrite  changes  into  native  copper,  melaconite, 
cuprite,  malachite,  chessylite,  or  perhaps  into  a  phos- 
phate, arsenate,  or  silicate  of  the  metal.  Carbonate  of 
manganese  gives  the  black  oxides  and  silver  sulphide 
ores  are,  after  weathering,  known  as  native  silver,  ke- 
rargyrite  and  embolite. 

The  ore  in  the  gossan  is  very  generally  more  valu- 
able than  it  will  be  below,  and  this  is  especially  true 
of  gold  and  silver  ores.  The  gold  having  been  set  free 
from  the  close  embrace  in  which  the  iron  pyrite  held  it 
previous  to  the  latter's  oxidation,  it  is  now  readily 
caught  by  quicksilver.  Silver  under  similar  condi- 
tions becomes  chloride,  and  likewise  amalgamates 
without  difficulty. 

Seams  containing  native  sulphur  often  show  no  trace 
of  that  element  on  the  surface,  having  weathered  into 
a  soft,  white,  gray  or  yellowish-white  granular,  or  pul- 
verulent, variety  of  gypsum. 

Veins  of  asbestos  often  decompose  into  a  white  pow- 
der found  in  the  crevices  of  the  rocks ;  fibrous  asbestos 
existing  in  the  interior. 

Petroleum  shows  in  an  iridescent  film  upon  still 
pools,  and  the  odor  is  a  sure  guide  to  its  nature. 

A  "dipping-needle"  is  valuable  to  the  prospector  on 


30  ABC   OF    MINING. 

the  lookout  for  iron  ore;  by  its  use  he  may  discover 
masses  of  magnetic  ore  and  trace  their  extent.  As  he 
carries  the  compass  over  the  ground  the  needle  dips 
toward  any  iron  mass  he  approaches;  directly  over  the 
ore  it  becomes  vertical. 

In  a  wilderness  country  strength  of  body  and  en- 
durance are  important  qualificatfons.  The  prospector 
must,  moreover,  have  such  general  knowledge  of  geol- 
ogy and  mineralogy  as  to  be  able  to  recognize  all  valu- 
able minerals  and  confirm  his  conjecture  by  simple 


MINER'S    DIPPING   NEEDLE. 

tests.  Pick,  shovel  and  pan  must  be  handled  skill- 
fully, while  the  rifle,  shotgun  and  paddle  must  also  be 
understood.  For  in  the  unsettled  parts  of  the  country 
the  traveler  must  even  yet  rely  to  some  extent  upon 
the  fish  and  game  he  may  be  able  to  secure,  and  every 
old  prospector  becomes  a  trained  hunter  and  camper. 
Knowing  how  to  bake  bread  is  sometimes  more  valu- 
able than  much  mathematics;  ability  to  build  a  rough 
boat  is  often  the  one  hope  of  salvation. 


PROSPECTING.  31 

In  sinking  a  short  shaft  in  a  sunny  country  a  large 
mirror,  inclined  at  a  suitable  angle  over  the  shaft,  will 
give  sufficient  light. 

Lodes  or  veins  following  the  general  trend  of  the 
auriferous  quartz  are  much  more  likely  to  be  rich  than 
are  those  that  cross  it.  Gold  is  never  distributed 
evenly  in  veins,  though  it  may  be  in  great  beds  of  low 
grade  material ;  but  more  often  rich  areas  alternate  with 
barren  portions. 

Where  quartz  veins  are  small  and  the  rich  pockets 
separated  by  wide  intervals  of  poor  gangue  the  gravel 
of  the  district  will  usually  be  similar  in  character.  As 
this  condition  obtains  in  the  upper  Yukon  district  as 
far  as  the  gravels  are  concerned,  it  will  probably  be 
found  to  hold  good  for  the  quartz  leads,  wEen  they 
shall  have  been  discovered. 

The  more  nearly  the  gold  formation  approaches  to 
the  crystalline  schists,  the  poorer  will  the  quality  of  the 
gold  be  through  the  larger  percentage  of  silver  found 
in  it.  In  slates  the  proportion  may  be  22  gold  to  I 
silver;  in  schists  it  has  been  known  to  be  a  ratio  of 
i  to  i. 

With  the  discovery  of  valuable  gold-bearing  gravel 
on  the  bare  hillsides  of  the  Northwest,  a  vast  region 
has  been  added  to  the  area  the  prospector  may  explore 
to  advantage.  No  experience  acquired  in  ordinary 
American  placer  grounds  is  likely  to  be  of  much  use 
in  detecting  these  higher  gold-bearing  gravels  of  the 
Yukon,  but  they  appear  to  be  somewhat  similar  in 
character  to  the  New  Zealand  terraces.  Terrace-pros- 
pecting requires  perseverance  and  the  use  of  some 


32  ABC  OF   MINING. 

brains,  as  it  is  infinitely  harder  than  creek-prospecting. 
These  terraces  or  benches  are  the  remains  of  old  river 
beds.  The  whole  bench  must  be  carefully  scanned 
over  because  the  gold  is  quite  as  likely  to  be  in  one 
part  as  in  the  other.  Sometimes  it  is  in  half  a  dozen 
different  layers  one  above  the  other.  Sometimes  the 
old  river  terraces  are  entirely  covered  by  landslides, 
and  the  majority  of  such  deposits  are  not  likely  ever 


DOLLY. 

to  be  found,  as  it  is  almost  impossible  to  guess  at  loca- 
tions. 

In  New  Zealand  gold  has  been  found  on  table-lands 
nearly  6,000  feet  above  sea  level,  and  according  to 
recent  information  valuable  claims  have  been  discov- 
ered in  Alaska  on  the  very  summits  of  the  rounded 
hills  on  each  side  of  El  Dorado  creek. 

To  understand  how  such  deposits  as  those  of  the 
Northwest  may  have  been  made,  suppose  that  such  a 
vein  as  that  of  the  Idaho,  which  has  been  worked 
for  a  depth  1,700  feet  by  a  width  of  1,000  feet,  and 


PROSPECTING.  33 

from  which  $17,000,000  have  been  taken,  to  have  been 
worn  down  by  glacial  or  other  forces.  Is  it  not  con- 
ceivable that  the  gold  would  gradually  have  accumu- 
lated in  the  nearest  canyon? 

To  obtain  suitable  samples  of  the  vein  a  dolly  is  an 
efficient  apparatus. 

This  is  practically  a  very  simple,  crude,  stamp  mill. 
On  the  end  of  a  solid  log,  firmly  fixed  in  the  ground 
and  standing  four  feet  or  so  above  the  surface,  a  square 
6-inch  hole  is  cut  in  which  are  fitted'  wrought  iron  bars 
3  inches  deep  by  ^  inch  wide,  and  separated  by  equal 
intervals.  These  bars  taper  below  so  as  to  permit  free 
passage  of  the  pounded  mineral.  A  wooden  box  sur- 
rounding the  grating  keeps  the  ore  in  place.  A  block 
of  wood,  shod  with  iron,  forms  the  stamper.  The 
miner  hauls  on  the  handles  at  every  blow.  The  gold 
is  saved  on  the  lower  table. 

No  one  of  experience  in  mining  would  look  for 
brown  hematite  in  a  granite  range,  nor  for  black  band, 
though  such  might  be  a  likely  region  for  red  hematite 
or  magnatite. 

The  explorer  should  be  familiar  in  theory  at  least 
with  the  locality  where  he  may  expect  to  find  valuable 
minerals.  For  instance,  should  he  be  searching  for 
some  heavy,  detached  substance  that  is  usually  found 
in  placer  deposits  he  will  keep  to  the  low  ground  and 
examine  carefully  the  beds  of  the  streams.  On  the 
other  hand,  should  his  quest  be  for  some  ore  that  is 
more  properly  a  component  of  a  lode  or  vein  he  will 
examine  the  side  hills  and  summits  where  denudation 
will  certainly  have  exposed  such  deposits.  Then  he 


34  .  ABC   OF   MINING. 

must  know  the  appearance  of  each  ore,  and  with  the 
methods  of  making  rough  and  ready  tests  he  must  be 
perfectly  familiar. 

Gold  is  always  more  or  less  intimately  associated 
with  quartz.  Oxide  of  tin  is  said  never  to  have  been 
found  more  than  two  miles  from  some  granite  rock, 
one  of  the  components  of  which  was  muscovite  or 
white  mica.  The  junction  of  slates  and  schists  with 
igneous  or  metamorphic  rocks  often  proves  a  valuable 
find  of  mineral. 

Rocks  for  the  purposes  of  the  explorer  may  be 
grouped  under  three  heads:  Igneous;  metamorphic; 
stratified.  The  first  includes  lavas;  trachytes,  grayish 
with  rough  fracture  and  mainly  glassy;  dark  basalts; 
and  traps,  such  as  greenstone.  Obsidian  is  a  volcanic 
glass.  Metamorphic  rocks  are  thought  to  have  once 
been  stratified,  but  to  have  been  altered  by  heat.  They 
comprise  granite,  of  quartz  feldspar  and  mica;  syenite, 
containing  hornblende  instead  of  mica;  gneiss,  like 
granite,  but  showing  lines  of  stratification;  mica  schist, 
made  up  of  mica  and  quartz  and  separating  easily  into 
layers;  slates. 

Stratified  rocks  are  those  deposits  from  water,  such 
as  sandstone,  limestone,  clay,  etc. 

A  prospecting  shaft  need  not  be  of  large  dimensions. 
One  4  feet  square  is  amply  large  for  any  depth  down 
to  30  feet,  but  it  must  be  kept  plumb. 

Sometimes  shafts  are  sunk  through  the  pay  streak 
in  alluvial  gravel,  without  it  being  detected.  Frequent 
panning  will  guard  against  this  mistake. 

In  the  Klondike  region  it  is  said  early  prospectors 


PROSPECTING.  35 

missed  very  rich  deposits,  that  have  since  been  discov- 
ered, by  stopping  short  of  true  be.d  rock,  being  misled 
by  a  bed  of  harder  gravel  that  they  thought  was  bot- 
tom. 

Silver  almost  invariably  carries  some  gold.  The 
dark  ironstone  hat  already  referred  to  is  a  good  indi- 
cation of  silver  ore  beneath ;  it  is  generally  composed 
of  conglomerates  cemented  by  oxides  of  iron  and  man- 
ganese. 

Galena,  which  is  sometimes  so  rich  in  silver  as  to  be 
worth  working  for  that  metal,  may  often  be  followed 
by  surface  indications;  namely,  a  white  limy  track 
with  detached  fragments  of  float  ore  in  the  surface  soil. 
The  blowpipe  or  fire  assay  quickly  determines  silver 
ore. 

Tin  in  lode,  stream,  or  alluvial  deposits  occurs  only 
as  an  oxide,  but  its  appearance  is  varied.  It  may  be 
almost  any  color  and  shape.  It  is  always  near  granite, 
containing  white  mica  known  as  muscovite. 

The  minerals  for  which  it  is  most  easily  mistaken 
are: 

Sp.  gravity.  Streak. 

Wolfram  7  to  7^  Red,  brown  or  black. 

Rutile  4.2  Light  brown. 

Tourmaline  3.2  Whitish. 

Black  Jack  4.3  Yellow,  white. 

The  magnetic  or  dipping  needle  is  used  in  New  Jer- 
sey, as  follows,  according  to  the  State  Geologist,  W. 
H.  Scranton,  M.  E.:  "An  attraction  which  is  con- 
fined to  a  very  small  spot  and  is  lost  in  passing  a  few 
feet  from  it,  is  most  likely  to  be  caused  by  a  boulder  of 


36  ABC  OF  MINING. 

ore  or  particles  of  magnetite  with  rock.  An  attraction 
which  continues  on  steadily  in  the  direction  of  the 
strike  of  the  rock  for  a  distance  of  many  feet  or  rods, 
indicates  a  vein  of  ore;  and  if  it  is  positive  and  strong- 
est towards  the  southwest,  it  is  reasonable  to  conclude 
that  the  vein  begins  with  the  attraction  there.  If  the 
attraction  diminishes  in  going  northwest,  and  finally 
dies  out  without  becoming  negative,  it  indicates  that 
the  vein  has  continued  on  without  break  or  ending 
until  too  far  off  to  move  the  compass  needle.  If,  in 
passing  towards  the  northwest,  along  the  line  of  at- 
traction, the  south  pole  is  drawn  down,  it  indicates  the 
end  of  the  vein  or  an  offset.  If,  on  continuing  further, 
still  in  the  same  direction,  positive  attraction  is  found, 
it  shows  that  the  vein  is  not  ended,  but  if  no  attraction 
is  shown,  there  is  no  indication  as  to  the  continuance 
of  the  ore. 

"In  crossing  veins  of  ore  from  southwest  to  north- 
west, when  the  dip  of  the  rock  and  ore  is  as  usual  to 
the  southeast,  positive  attraction  is  first  observed  to 
come  on  gradually,  and  the  northwest  edge  of  the  vein 
is  indicated  by  the  needle  suddenly  showing  negative 
attraction  just  at  the  point  of  passing  off  it.  This 
change  of  attraction  will  be  less  marked  as  the  depth 
of  the  vein  is  greater,  or  as  the  strike  is  nearer  north 
and  south.  The  steadiness  and  continuance  of  the 
attraction  is  a  much  better  indication  of  ore  than  the 
strength  or  amount  of  the  attraction.  The  ore  may 
vary  in  its  susceptibility  to  the  magnetic  influence  from 
impurities  in  its  substance;  it  does  vary  according  to 
the  position  in  which  it  lies,  that  is  according  to  its 


PROSPECTING.  37 

dip  and  strike;  and  it  also  varies  very  much  accord- 
ing to  its  distance  beneath  the  surface." 

Further  instructions  are  given  in  the  paper  from 
which  the  foregoing  extract  was  taken,  some  of  which 
follow : 

"It  is  sufficient  to  say  that  the  first  examinations  are 
made  by  passing  over  the  ground  with  the  compass  in 
a  northwest  and  southwest  direction,  at  intervals  of  a 
few  rods,  until  indications  of  ore  are  found.  Then  the 
ground  should  be  examined  more  carefully  by  crossing 
the  line  of  attraction  at  intervals  of  a  few  feet,  and 
marking  the  points  upon  which  observations  have  been 
made,  and  recording  the  amount  of  attraction.  Obser- 
vations with  the  ordinary  compass  should  be  made, 
and  the  variation  of  the  horizontal  needle  be  noted. 
In  this  way  materials  may  soon  be  accumulated  for 
staking  out  the  line  of  attraction,  or  for  constructing  a 
map  for  study  or  reference. 

"After  sufficient  exploration  with  the  magnetic 
needle,  it  still  remains  to  prove  the  value  of  the  vein 
by  uncovering  the  ore,  examining  its  quality,  measur- 
ing the  size  of  the  vein,  and  estimating  the  cost  of 
mining  and  marketing  it.  Uncovering  should  first  be 
done  in  trenches  dug  across  the  line  of  attraction,  and 
carried  quite  down  to  the  rock.  When  the  ore  is  in 
this  way  proved  to  be  of  value  regular  mining  may  be- 
gin. In  places  where  there  are  offsets  in  the  ore,  or 
where  it  has  been  subject  to  bends,  folds,  or  other  ir- 
regularities, so  that  the  miner  is  at  fault  in  what  direc- 
tion to  proceed,  explorations  may  be  made  with  the 
diamond  drill," 


38  ABC   OF   MINING. 


CHAPTER  II. 
HOW  TO  TEST   FOR    MINERALS. 

When  the  mineralogist  wishes  to  know  the  names  of 
the  specimen  he  holds  in  his  hand,  he,  in  the  case  of  a 
mineral  difficult  to  determine,  considers  all  the  follow- 
ing properties: 

Crystalline  form  and  structure, 

Cleavage, 

Fracture, 

Tenacity, 

Hardness, 

Specific  Gravity  as  compared  with  that  of  water, 

Luster, 

Color  and  Streak, 

Transparency  or  otherwise, 

Taste, 

Odor, 

Chemical  Composition  tested  by  analysis, 

Pyrognostic  characters  as  determined  by  the  use  of 
the  blowpipe, 

Mode  of  occurrence  and  associated  minerals. 

Crystalline  Form  and  Structure.  Unfortunately  the 
science  of  crystallography  is  extremely  complicated 
and  long  study  is  necessary  to  master  it;  once  acquired, 
however,  it  is  of  paramount  usefulness  to  the  student. 
According  to  Dana  there  are  six  systems,  to  one  of 
which  every  crystal  may  be  referred.  They  are: 


HOW  TO   TEST   FOR    MINERALS.  39 

Isometric;  (2)  Tetragonal;  (3)  Hexagonal  or  Rhom- 
bohedral;  (4)  Orthorhombic ;  (5)  Monoclinic;  (6)  Tri- 
clinic. 

In  the  isometric  system  there  are  three  equal  axes  at 
right  angles  to  each  other. 

In  the  tetragonal  system  there  are  three  axes  at  right 
angles  to  each  other.  Two  of  these  are  equal,  while 
the  third,  or  vertical  angle,  is  longer  or  shorter. 

There  are  two  divisions  of  the  hexagonal  system; 
the  hexagonal  system  properly  so-called,  and  its  rhom- 
bohedral  division.  All  forms  are  referred  to  four 
axes,  three  equal  axes  inclined  to  each  other  at  angles 
60  degrees  in  a  common  horizontal  plane,  and  a  fourth 
vertical  axis  at  right  angles,  and  longer  or  shorter. 
The  rhombohedral  division  comprises  crystals  having 
but  three  planes  of  symmetry,  intersecting  at  angles  of 
1 20  degrees  in  the  vertical  axis.  They  are  regarded 
as  half  forms  of  the  corresponding  hexagonal  crystals. 

In  the  orthorhombic  system  there  are  three  unequal 
axes  at  right  angles  to  each  other. 

In  the  monoclinic  system  there  are  three  unequal 
axes,  of  which  one,  the  lateral  axis,  is  inclined  to  the 
vertical,  while  the  angles  between  the  others  are  right 
angles. 

In  the  triclinic  system  there  are  three  unequal  axes 
and  these  intersections  are  all  oblique.  The  student 
who  wishes  to  pursue  this  subject  further  should  con- 
sult Dana's  System  of  Mineralogy. 

Physical  Mineralogy.  Cleavage  is  the  line  of  easi- 
est separation  in  a  mineral.  It  may  be  perfect,  im- 
perfect, interrupted,  etc. 


40  ABC   OF   MINING. 

Fracture,  referring  to  any  surface  except  that  of  a 
cleavage  fall,  may  be  uneven,  conchoidal  (shell-like), 
hackly  (rough),  etc. 

Tenacity  refers  to  such  qualities  as  brittle,  sectile, 
malleable,  flexible,  or  elastic. 

Hardness  is  represented  by  the  difficulty  with  which 
a  smooth  surface  is  scratched.  The  scale  in  general 
ore  was  devised  by  Mohs.  It  is: 

1.  Talc.     Scratched  by  the  ringer  nail. 

2.  Gypsum.     Ditto,  but  with  more  difficulty.    Will 
not  scratch  a  copper  coin. 

3.  Calcite.     Scratched  by  a  copper  coin. 

4.  Fluorite.     Is  not  scratched  by  a  copper    coin 
and  does  not  scratch  glass. 

5.  Apatite.     Scratches  glass,  but  with  difficulty.    Is 
re.adily  scratched  by  a  knife. 

6.  Feldspar.     Scratches  glass  with  ease.     Is  diffi- 
cult to  scratch  by  knife. 

7.  Quartz.     Cannot  be  scratched  by  a  knife  and 
readily  scratches  glass. 

8.  Topaz.     Harder. 

9.  Corundum.     Harder. 

10.  Diamond.     Scratches  any  other  substance. 
Hardness  may  be  intermediate.     For  instance,  any 

mineral  that  scratched  quartz  and  is  soft  enough  to 
be  scratched  by  topaz,  in  turn  would  be  rated  at  7.5. 

Specific  Gravity.  This  is  the  density  of  mineral  and 
other  substances  compared  with  that  of  water.  It  is 
particularly  valuable  in  determining  heavy  metals. 

To  find  the  specific  gravity  of  any  solid  body  divide 
its  weight  in  air  by  the  loss  of  weight  in  water,  at  a  tern- 


HOW  TO  TEST   FOR   MINERALS.  41 

perature  as  near  60  degrees  F.  as  possible,  and  the 
quotient  will  equal  the  specific  gravity.  In  the  case  of 
gases,  such  as  nitrogen,  oxygen,  etc.,  hydrogen  is 
taken  as  the  unit. 

Luster.  There  are  seven  kinds  of  luster,  viz:  Me- 
tallic, the  luster  of  metals;  adamantine,  that  of  the  dia- 
mond; vitreous,  of  broken  glass;  resinous,  of  the  yel- 
low resins;  greasy;  pearly;  silky.  There  are  five  de- 
grees of  intensity  of  luster  recognized,  viz:  Splendent'; 
shining;  glistening;  glimmering;  dull. 

Color  and  Streak.  The  streak  is  the  color  of  the 
powder  of  the  mineral  when  rubbed  on  unglazed  por- 
celain, or  scratched  with  a  knife. 

Transparency.  Minerals  may  be  transparent,  sub- 
transparent,  translucent,  sub-translucent,  opaque. 

Taste.     Minerals  may  be  salt,  bitter,  sweet,  etc. 

Odor.  This  test  is  not  of  much  use  with  most  min- 
erals until  heat  is  applied.  All  the  petroleum  oils, 
however,  are  often  detected  by  their  odor. 

Chemical  Composition.  This  may  always  be  deter- 
mined by  suitable  tests  with  reagents. 

Pyrognostic  Characters.  As  a  means  of  readily 
determining  the  nature  of  a  specimen  the  blowpipe  is 
unrivalled — if  in  the  hands  of  one  who  understands  it. 

Mode  of  occurrence  and  associated  minerals.  A 
knowledge  of  these  matters  often  assists  in  a  determi- 
nation. 

A  regular  fire  assay  is  not  within  reach  of  many 
prospectors,  for  the  necessary  apparatus  cannot,  as  a 
rule,  be  carried  in  the  wilderness.  Whenever  possible, 


42  ABC   OF    MINING. 

however,  a  fire  assay  gives  the  truest  results,  especially 
in  the  case  of  gold  and  silver. 


SCALE  FOR  WEIGHING   ORE. 

The  operation  includes  testing  the  ore,  sampling  and 
pulverizing,  weighing  the  ore  and  reagents,  calcina- 
tion and  roasting,  reduction  and  fusion,  distillation  and 
sublimation,  scorification  and  cupellation,  inquarta- 
tion  and  parting  the  gold  and  silver,  weighing  and  tab- 
ulating. "Notes  on  Assaying"  by  Dr.  Ricketts  is  a 
very  useful  manual  to  have  at  hand. 

A  TOLERABLY  COMPLETE  OUTFIT  IN- 
CLUDES: 

A  pair  of  scales  for  weighing  ore  and  buttons  of  base 
metal.  It  should  take  10  ounces  in  each  pan,  and  show 
I -20  of  a  grain. 


HOW  TO  TEST   FOR    MINERALS. 


43 


A  bullion  scale  to  be  kept  strictly  for  the  precious 
metals.  Loaded  with  one  gramme,  it  should  show 
i -20  of  a  milligramme. 

Weights.  Avoirdupois;  troy,  metric  and  "assay." 
Assay  weights  save  much  calculation.  The  unit  of  the 
system  is  a  weight  of  29.166  grammes.  Its  derivation 
is  as  follows: 


ASSAY  BALANCE  FOR  BULLION. 


2000  tbs.   :  I  A.  T.   : :  I  oz.  Troy   :  I  milligramme. 

To  use  this  system,  weigh  out  one  A.  T.  of  the  ore 
and  whatever  number  of  milligrammes  of  gold  and 
silver  the  assay  gives  indicates  an  equal  number  of 
Troy  ounces  to  the  ton  of  2000  Ibs.  Avoirdupois. 

A  muffle  and  a  melting  furnace,  portable  and  of  me- 
dium size,  are  handy,  though  furnaces  may  be  built 


44 


ABC   OF   MINING. 


of  ordinary  brick,  lined  with  fire  brick,  that  would  be 
better  for  permanent  use. 

The  fuels  may  be  coke,  anthracite  or  bituminous 
coal,  charcoal,  oil  or  gas. 


PORTABLE  ASSAY  FURNACE. 


HOW  TO  TEST  FOR   MINERALS. 


Crucibles  of  black  lead,  French  clay,  Hessian  sand, 
and  quicklime  are  necessary  to  hold  the  assay. 


French  Clay. 


Hessian. 


CRUCIBLES. 


Roasting  di&hes,  scorifiers  and  cupels  are  required. 
The  cupel  is  made  of  the  ashes  of  burnt  bone,  and  it 


SCORIFIER 


STEEL    CUPEL    MOULD. 


40  ABC  OF   MINING. 

is  better  to  make  them  on  the  spot,  as  the  bone  ash 
may  be  carried  anywhere  without  damage,  whereas 
the  cupels  are  very  fragile.  The  bone  ash  is  moistened 


SCORIFICATION  FURNACE. 


with  water,  stamped  in  a  cupel  mould,  and  allowed  to 
dry  slowly.    A  good  one  will  absorb  its  own  weight 


SCORIFICATION    MOULD. 


of  lead,  but  it  is  better  to  calculate  on  its  absorbing  but 
three-quarters  of  that  amount. 

The  crucible,  scorification  and  cupel  tongs,  a  couple 


HOW  TO  TEST   FOR    MINERALS. 


47 


of  hammers,  iron  pestle  and  mortar,  sieves  from  20  to 
100  mesh,  and  scorification  mould  complete  the  requi- 
site tools. 


HAMMER. 


In  addition,  however,  the  assayer  will  require  quite 
a  bulky  lot  of  apparatus,  reagents  and  chemicals.  All 
dealers  keep  lists  of  assayers'  supplies  on  hand,  and  a 


HORN  SPOON. 


full  and  complete  assortment  will  cost  about  $200  in 
New  York  or  Chicago.  Quart  bottles,  with  glass  stop- 
pers; ordinary  corked  bottles,  ring  stands,  alcohol 


STEEL   MORTAR. 


ALCOHOL.  LAMP. 


ABC  OF  MINING. 

lamps,  wash  bottles,  test  tubes,  horn 
spoons,  iron  pans,  parting  flasks,  anneal- 
ing cups,  glazed  black  paper — these  will 
suffice,  provided  the  assayer  has,  as  well, 
the  outfit  recommended  for  blow-pipe 
work. 

Dry  reagents,  such  as  litharge,  borax 
(crystallized),  silica,  cyanide  of  potassium, 
yellow  prussiate  of  potash,  argol,  charcoal, 
starch,  metallic  iron,  pure  lead,  nitre,  pow- 
dered lime,  sulphur,  carbonate  of  ammonia 
and  common  salt  are  necessary.  As  sol- 
vents and  precipitants,  distilled  water,  sul- 
phuric, nitric  and  hydrochloric  acids,  chlor- 
ide of  sodium,  nitrate  of  silver  and  sulphu- 
retted hydrogen  are  also  indispensable. 

This  will  seem  rather  a  formidable  list, 
TESTTUBE.  and  so,  under  certain  conditions,  it  may  be ; 
indeed,  where  means  of  transport  is  lim- 
ited, all  regular  assay  work  must  be  postponed  until 
the  return  to  civilization.  Assaying  is  not,  however, 
difficult,  being  mostly  a  matter  of  rule  of  thumb,  and 
correct  results  may  be  arrived  at  without  a  deep 
knowledge  of  chemistry,  although  such  knowledge  will 
never  come  amiss. 

A  preliminary  examination  will  show  what  the  ore 
probably  is.  The  blow-pipe  is  especially  useful,  though 
to  the  skilled  assayer  often  unnecessary.  The  ore  is 
first  powdered,  and  any  metallic  flakes  picked  out 
and  tested  separately.  A  fair  sample  must  be  selected, 
otherwise  all  the  work  will  be  thrown  away  and  the 
result  be  valueless. 


HOW  TO  TEST  FOR   MINERALS.  49 

The  next  step  is  weighing  the  ore  and  the  reagents. 
Moisture  is  drawn  off  by  heating  in  a  crucible,  a  low 
heat  being  sufficient.  Roasting  will  eliminate  sulphur, 
antimony,  arsenic,  etc.,  and  must  take  place  in  a  "flat 
dish,  so  that  the  air  may  have  free  access.  The  powder 
should  be  stirred  frequently. 

Reduction  is  the  operation  of  removing  oxygen,  and 
it  takes  place  usually  in  a  crucible  or  scorifier. 

Scorification  consists  in  placing  the  ore  in  an  open 
dish  with  proper  reagents,  and  collecting  all  the  vola- 
tile ingredients  in  the  slag.  Cupellation,  on  the  other 
hand,  collects  them  in  the  bone  ash,  of  which  the  cupel 
is  composed. 

When  silver  must  be  separated  from  gold,  it  is 
sometimes  convenient  to  increase  its  proportion  by  the 
addition  of  some  known  weight  of  the  inferior  metal. 
After  fusing,  the  globule  is  placed  in  nitric  acid,  and 
the  silver  parted  from  the  gold,  which  may  then  be 
weighed.  This  result  subtracted  from  the  weight  of 
the  original  globule  gives  the  amount  of  silver. 

To  test  an  ore  for  gold,  take  a  pound  of  it,  crush  in 
mortar  and  pass  through  a  fine  sieve.  Take  one- 
fourth  ounce  Troy  of  the  powder.  Place  in  scorifier 
with  an  equal  amount  of  litharge.  Cover  with  borax 
that  has  been  melted  and  powdered,  and  put  the  scori- 
fier in  the  muffle  of  the  furnace.  A  blacksmith's  forge 
might  do  at  a  pinch.  Heat  until  the  mass  has  become 
a  fluid,  possibly  twenty  or  thirty  minutes.  Next  pour 
into  the  scorification  mould,  and,  after  the  slag  has  set, 
remove  it  with  a  hammer.  Hammer  the  button  into 
a  cube  and  place  it  in  the  cupel,  which  must  first  have 
4 


SO  ABC  OF  MINING. 

been  thoroughly  heated.  Heat  until  all  the  base  metal 
has  been  absorbed  by  the  cupel  and  the  button  has 
"brightened,"  or  flashed;  when  this  occurs,  remove 
the  cupel  to  the  front  of  the  muffle,  cool,  and  remove 
the  button  with  pincers.  Weigh  it,  and  you  have  the 
amount  of  gold  and  silver  in  Bounce  Troy.  A  simple 
sum  in  proportion  gives  the  amount  in  a  ton. 

All  ores  containing  sulphur,  arsenic,  antimony,  or 
zinc,  should  be  roasted. 

There  are  three  stages  in  the  scorification  process; 
roasting,  fusion,  and  scorification.  During  the  first, 
the  heat  should  be  moderate  until  fumes  cease  to  be 
given  off;  during  the  second,  the  heat  is  raised  and  a 
play  of  colors  is  seen  on  the  surface  of  the  lead;  in  the 
closing  stage,  the  heat  is  lowered  for  a  time  until  the 
slag  covers  the  lead,  when  it  is  again  raised  for  a 
short  time  and  the  scorifier  removed.  Brittle  buttons 
may  be  due  to  arsenic,  antimony,  zinc  or  litharge,  and 
must  be  re-scorified  before  cupellation,  with  more  lead. 

Take  the  cupel  slowly  from  the  fire  to  avoid  "spit- 
ting," by  which  portions  of  the  buttons  are  lost. 
Watch  closely  for  the  brightening. 

Silver  is  volatile  at  a  high  heat,  but  when  the  muf- 
fle is  almost  white,  the  metal  well  fused  and  clean,  the 
fumes  rising  slowly,  and  the  cupel  a  cherry  red,  all  is 
going  smoothly.  If  the  fumes  rise  rapidly,  the  muffle 
is  too  hot.  On  the  other  hand,  dense,  falling  fumes 
show  the  temperature  is  too  low.  Lead  that  is  poor 
in  silver  stands  the  highest  heat  without  vitiating  the 
assay. 

When  the  material  in  the  cupel  "freezes,"  i.  e.,  the 


HOW  TO  TEST   FOR   MINERALS.  51 

absorption  by  the  cupel  stops,  reject  the  assay  and  try 
again,  giving  more  heat  or  more  lead. 

Gold.  Practically,  the  metal  most  prospectors  seek 
is  gold.  It  is  so  enormously  valuable  and  constitutes 
so  very  small  a  percentage  of  any  ore,  that  care  must 
be  taken  or  it  may  escape  detection  and  be  lost.  Pan- 
ning is  the  miner's  method.  He  crushes  his  ore  thor- 
oughly, and  places  it  in  the  pan  with  water;  then,  with 
a  motion  easy  to  learn  but  difficult  to  describe,  he 
swirls  the  water  around,  allowing  a  little  of  it  to  es- 
cape at  each  revolution,  carrying  with  it  the  rubbish, 
until  finally  he  has  a  little  black  sand  and  perhaps  a 
few  grains  of  yellow  substance,  which  is  gold.  Mica, 
or  fool's  gold,  puzzles  nobody  but  the  ignoramus. 
True,  it  looks  like  gold  in  certain  positions  and  lights, 
but  gold  will  beat  out  thin  under  the  hammer,  just  as 
lead  would,  while  mica  will  break  up  into  a  floury 
powder.  Mica  is  very  light,  while  gold  is  very  heavy; 
so  there  is  no  excuse  for  confounding  the  two.  If  an 
ore  contains  sulphurets  and  gold,  the  latter  may  be 
coated  with  some  sulphur  or  arsenic,  which  would  pre- 
vent the  gold  from  amalgamating.  The  only  remedy 
for  this  is  roasting.  No  single  acid  will  dissolve  gold, 
but  a  solution  known  as  aqua  regia,  made  up  of  three 
parts  of  hydrochloric  acid  and  one  part  of  nitric  acid, 
dissolves  it.  If  to  the  solution  so  obtained  you  add 
some  sulphate  of  iron,  you  will  get  a  precipitate  which 
is  metallic  gold,  although  it  does  not  look  like  it,  as 
it  is  brown  in  color;  but  if  you  place  this  precipitate 
in  a  crucible  and  heat,  you  will  get  a  yellow  bead  of 
pure  gold.  Another  test  for  gold  is  to  take  the  solution 


52  ABC   OF   MINING. 

as  above  obtained  and  add  thereto  a  solution  of  chlo- 
ride of  tin,  when  you  obtain  a  purple  coloration  that 
has  been  called  the  purple  of  Cassius. 

Gold  may  be  distinguished  from  all  other  metals  by 
the  three  following  tests:  It  is  yellow;  it  may  be  flat- 
tened by  the  hammer;  it  is  not  acted  upon  by  nitric 
acid. 

Pure  gold  is  soft,  and  the  point  of  a  knife  will  scratch 
it  deeply.  Pounded  in  a  mortar,  the  pulverized  mineral 
should  be  passed  through  a  cheese-cloth  screen 
stretched  over  a  loop  of  wood.  If  the  course  contains 
much  pyrite,  it  must  be  roasted  before  washing  in  the 
pan  and  amalgamating.  Sample  well,  weigh  out  two 
pounds,  put  it  in  a  black  iron  pan,  with  four  ounces 
of  mercury,  four  ounces  of  salt,  four  ounces  of  soda 
and  a  half  gallon  of  boiling  water.  Stir  with  a  green 
stick,  and  agitate  until  the  mercury  has  been  able  to 
reach  all  the  gold.  Pan  off  into  another  dish  so  as 
to  lose  no  mercury,  squeeze  the  amalgam  through 
chamois  leather  or  new  calico  previously  wetted.  The 
pill  of  hard  amalgam  may  be  placed  on  a  shovel 
over  the  fire  or  in  a  clay  tobacco  pipe  and  retorted. 

Gold  is  readily  acted  upon  by  the  mixture  of  nitric 
and  hydrocloric  acids  known  as  aqua  regia,  or  by  any 
solution  producing  chlorine.  Some  of  the  mixtures 
which  attack  it  are  bisulphate  of  soda,  nitrate  of  soda 
and  common  salt,  hydrochloric  acid  and  potassium 
chlorate,  and  bleaching  powder.  The  action  is  more 
rapid  in  hot  than  in  cold  solutions,  and  impure  gold 
is  more  easily  dissolved  than  pure. 

Mercury  dissolves  gold  rapidly  at  ordinary  tempera- 


HOW  TO  TEST   FOR    MINERALS.  53 

tures,  the  amalgam  being  solid,  pasty  or  liquid.  Gold 
rubbed  with  mercury  is  immediately  penetrated  by  it. 
An  amalgam  containing  90  per  cent  of  mercury  is 
liquid;  87.5  per  cent.,  pasty;  85  per  cent.,  crystalline. 
These  amalgams  heated  gradually  to  a.  bright  red  heat 
lose  all  their  mercury,  and  hardly  any  gold.  About 
one-tenth  of  I  per  cent,  of  mercury  remains  in  the 
gold  until  it  is  refined  by  melting. 

The  veins  from  which  the  gold  of  the  world  is  won 
do  not,  on  an  average,  hold  the  precious  metal  in 
greater  proportion  than  one  part  of  gold  in  70,000 
parts  of  veinstone.  Under  favorable  conditions  a  pro- 
portion not  one-fifth  as  rich  as  this,  may  yield 
a  rich  return.  In  hydraulic  mining  on  a  large  scale, 
one  part  of  gold  in  15,000,000  parts  of  gravel  has  paid 
a  dividend. 

A  test  known  as  Darton's  is  believed  to  be  a  valu- 
able means  of  detecting  minute  quantities  of  gold  in 
rocks,  ore  tailings,  etc. 

"Small  parts  are  chipped  from  all  the  sides  of  a 
mass  of  rock,  amounting  in  all  to  about  |  ounce.  This 
is  powdered  in  a  steel  mortar  and  well  mixed.  About 
•half  is  placed  in  a  capacious  test  tube,  and  then  the 
tube  is  partly  filled  with  a  solution  made  by  dissolving 
20  gr.  of  iodine  and  30  gr.  of  iodide  of  potassium,  in 
about  i^  ounces  water.  The  mixture  thus  formed  is 
shaken  and  warmed.  After  all  particles  have  subsided, 
dip  a  piece  of  fine  White  filter  paper  in  it;  allow  it  to 
remain  for  a  moment ;  then  let  it  drain,  and  dry  it  over 
the  spirit  lamp.  It  is  next  placed  upon  a  piece  of 
platinum  foil  held  in  a  pincers,  and  heated  to  redness 


54  ABC   OF   MINING. 

over  the  flame.  The  paper  is  speedily  consumed;  and 
after  again  heating  to  burn  off  all  carbon,  it  is  allowed 
to  cool  and  is  then  examined.  If  at  all  purple,  gold  is 
present  in  the  ore,  and  the  relative  amount  may  be 
approximately  deduced.  This  method  takes  little  time, 
and  is  trustworthy." 

Black  sand,  which  is  iron,  often  with  some  platinum 
and  iridium,  sometimes  interferes  with  the  result  of  a 
gold  assay.  Attwood  recommends  the  following 
method  as  applicable  to  such  a  case: 

"Take  100  to  1000  grains  and  attack  with  aqua  regia 
in  a  flask ;  cool  for  about  thirty  minutes  or  more ;  di- 
lute with  water  and  filter.  If  gold  is  present,  it  will 
now  be  held  in  solution  in  the  filtrate.  Remove  the 
filter  and  evaporate  the  filtrates  to  dryness;  then  add 
a  little  hydrochloric  acid,  evaporate  and  re-dissolve 
the  dry  salt  in  warm  water ;  add  to  the  solution  so 
formed  proto-sulphate  of  iron  ;  which  will  throw 
down  the  gold  in  the  form  of  a  fine,  dark  precipitate. 
The  precipitate  is  seldom  fine,  being  mixed  with  ox- 
ides of  iron,  and  must  now  be  dried  in  the  filter  paper, 
and  both  burned  over  the  lamp  in  a  porcelain  dish. 
Then  mix  the  dried  precipitate  with  three  times  its 
weight  of  lead;  fuse,  scorify  and  cupel.  In  case  plati- 
num, iridium,  etc.,  are  found  associated  with  the  gold, 
an  extra  amount  of  fine  silver  should  be  added  before 
cupellation,  and  the  gold  button  will  be  found  pure." 

In  one  of  his  reports  the  State  Mineralogist  of  Cali- 
fornia gives  a  most  lucid  description  of  a  mechanical 
assay  of  gold-bearing  sands,  stamped  ore,  etc.,  etc.  He 
states: 


HOW  TO  TEST   FOR    MINERALS.  55 

"It  must  be  understood  that  this  is  only  a  working 
test.  It  does  not  give  all  the  gold  in  the  rock,  as 
shown  by  a  careful  fire  assay,  but  what  is  of  equal  im- 
portance to  the  mine-owner,  mill-man,  and  practical 
miner,  it  gives  what  he  can  reasonably  expect  to  save 
in  a  good  quartz  mill.  It  is  really  milling  on  a  small 
scale.  It  is  generally  very  correct  and  reliable,  if  a 
quantity  of  material  be  sampled.  The  only  operation 
which  requires  much  skill  is  the  washing,  generally 
well  understood  by  those  who  are  most  likely  to  avail 
themselves  of  the  instructions.  These  rules  apply 
equally  to  placer  gravels.  Take  a  quantity  of  the  ore 
— the  larger  the  better — and  break  it  into  egg-sized 
pieces.  Spread  on  a  good  floor,  and  with  a  shovel  mix 
very  thoroughly;  then  shovel  into  three  piles,  placing 
one  shovelful  upon  each  in  succession  until  all  is  dis- 
posed of.  Two  of  the  piles  may  then  be  put  into  bags. 
The  remaining  pile  is  spread  on  the  floor,  mixed  as 
before,  and  shovelled  in  the  same  manner  into  three 
piles.  This  is  repeated  according  to  the  quantity  sam- 
pled, until  the  last  pile  does  not  contain  more  than 
30  pounds  of  ore.  As  the  quantity  on  the  floor  be- 
comes smaller,  the  lumps  must  be  broken  finer  until 
at  last  they  should  not  exceed  one  inch  in  diameter. 
The  remainder  is  reduced  by  a  hammer  and  iron  ring 
to  the  size  of  peas.  The  whole  30  pounds  is  then  spread 
out,  and  after  careful  mixing  portions  are  lifted  with 
a  flat  knife,  taking  up  the  fine  dust  with  the  larger 
fragments,  until  about  10  pounds  have  been  gathered. 
This  quantity  is  then  ground  down  fine  with  the  mul- 
ler,  and  passed  through  a  4O-mesh  sieve.  If  the  rock 


56  ABC   OF    MINING. 

is  rich,  the  last  portion  will  be  found  to  contain  some 
free  gold  in  flattened  discs,  which  will  not  pass  this 
sieve.  These  must  be  placed  with  the  pulverized  ore, 
and  the  whole  thoroughly  mixed,  if  the  quantity  is 
small,  but  if  large  must  be  treated  separately,  and  the 
amount  of  gold  allotted  to  the  whole  10  pounds  and 
noted  when  the  final  calculation  is  made. 

"From  the  thoroughly-mixed  sample,  two  kilo- 
grammes (2000  grammes)  must  be  carefully  laid  out. 
This  is  placed  in  a  pan  or,  better,  in  a  batea,  and  care- 
fully washed  down  until  the  gold  begins  to  appear. 
Clean  water  is  then  used,  and,  when  the  pan  and  the 
small  residue  are  cleaned,  most  of  the  water  is  poured 
off  and  a  globule  of  pure  mercury  (which  must  be  free 
from  gold)  is  dropped  in,  a  piece  of  cyanide  of  potas- 
sium being  added  with  it.  As  the  cyanide  dissolves,  a 
rotary  motion  is  given  the  dish,  best  done  by  holding 
the  arms  stiff  and  moving  the  body.  As  the  mercury 
rolls  over  and  ploughs  through  the  sand,  under  the 
influence  of  the  cyanide  it  will  collect  together  all  the 
particles  of  free  gold.  When  it  is  certain  that  all  is 
collected,  the  mercury  may  be  carefully  transferred  to 
a  small  porcelain  cup  or  test  tube,  and  boiled  with 
strong  nitric  acid,  which  must  be  pure.  When  the 
mercury  is  all  dissolved  the  acid  is  poured  off,  more 
nitric  acid  applied  cold,  and  rejected,  and  the  gold  is 
then  washed  \vith  distilled  water  and  dried. 

"The  object  of  w-ashing  with  acid  the  second  time  is 
to  remove  any  nitrate  of  mercury  which  might  remain 
with  the  gold,  and  which  is  immediately  precipitated 
if  water  is  first  used. 


HOW  TO  TEST   FOR    MINERALS.  57 

"The  resulting  gold  is  not  pure,  but  has  the  com- 
position of  the  natural  alloy.  Before  accurate  calcula- 
tions of  value  are  possible,  the  gold  must  be  obtained 
pure  and  weighed  carefully.  To  purify  the  gold  it 
should  be  melted  with  silver,  rolled  out  or  hammered 
thin,  boiled  twice  with  nitric  acid,  washed,  dried,  and 
heated  to  redness. 

"The  method  of  calculating  this  assay  is  simple.  It 
will  be  observed  that  2000  grammes  represent  a  ton 
of  2000  pounds;  then  each  gramme  will  be  the  equiva- 
lent of  one  pound  avoirdupois,  or  one  2OOOth  part  of 
the  whole,  and  the  decimals  of  a  gramme  to  the  deci- 
mals of  a  pound.  Suppose  the  ore  yielded  by  the  assay 
just  described,  fine  gold  weighing  .072  gramme,  it 
must  be  quite  evident  that  a  ton  of  the  ore  would 
yield  the  same  decimal  of  one  pound.  Now  one 
pound  of  gold  is  worth  $301.46,  and  it  is  only  necessary 
to  multiply  this  value  by  the  weight  of  gold  obtained 
in  grammes  and  decimals  to  find  the  value  of  the  gold 
in  a  ton  of  ore — $301.46  x  .072 — $21.70.  The  cyanide 
solution  should  be  kept  rather  weak,  as  gold  is  slightly 
soluble  in  strong  solutions  of  cyanide  of  potassium. 
Cyanide  is  a  deadly  poison." 

Touchstones  are  useful  in  deciding  the  probable 
value  of  gold  alloys.  Several  pieces  of  the  metal  un- 
der examination  are  cut  with  a  cold  chisel,  and  the 
fresh  edges  drawn  over  the  touchstone.  These  streaks 
are  touched  with  nitric  acid  on  a  glass  rod.  Should 
no  reaction  follow,  the  gold  is  at  least  640  fine.  Wipe 
the  stone  with  soft  linen  and  try  with  test  acid,  made 
by  mixing  98  parts  of  chemically  pure  nitric  acid 


58  ABC   OF   MINING. 

with  two  parts  of  hydrochloric  acid,  adding  25  parts 
distilled  water  by  measure.  If  this  has  no  effect,  take 
a  touch  needle  marked  700,  and  make  a  similar  streak 
on  the  stone  samples.  Compare,  and,  if  necessary, 
continue  with  the  other  needles,  using  a  higher  num- 
ber each  time.  An  approximate  estimate  of  the  sam- 
ple will  soon  be  obtained.  Should  the  gold  seem  poor- 
er than  640  fine,  try  with  the  copper  or  silver  needle. 
Practice  and  a  good  eye  soon  make  this  method  very 
certain  in  its  results. 

Retorted  amalgam  is  likely  to  contain  mercury.  To 
test  for  it,  put  a  small  fragment  into  a  closed  glass 
tube,  taking  care  that  it  falls  quite  to  the  botom.  Heat 
the  gold  over  a  spirit  lamp,  and  a  deposit  of  mercury 
will  soon  be  seen  upon  the  colder  sides  of  the  tube 
above  the  bottom.  The  tube  may  be  broken  and  the 
mercury  collected  into  a  globule  under  water. 

In  mining  regions  gold  dust  passes-  current  as  coin, 
according  to  what  is  supposed  to  be  its  value.  Occa- 
sionally counterfeit  dust  is  offered.  The  readiest 
means  by  which  it  may  be  detected  are  as  follows: 
The  dust  from  any  one  district  is  always  much  alike, 
and  any  unusual  appearance  should  create  suspicion. 
Try  any  doubtful  pieces  on  a  small  anvil,  remembering 
that  gold  is  extremely  malleable.  Test  some  of  the 
gold  with  nitric  acid;  effervescence  or  evolution  of  red 
fumes,  or  coloration  of  the  acid  prove  impurities  to  be 
present.  Place  two  watch-glasses  (most  useful  in  chem- 
ical tests)  on  paper;  the  one  on  a  white  sheet,  the  other 
on  a  black,  and  with  a  glass  rod  convey  a  few  drops  of 
nitric  acid  from 'the  dish  to  each.  To  the  glass  on 


HOW   TO  TEST   FOR   MINERALS.  59 

white  paper  add  a  drop  or  two  of  ammonia;  a  blue 
color  would  indicate  copper.  To  the  other  add  hydro- 
chloric acid ;  should  a  white  precipitate  form,  it  proves 
silver.  If  no  action  is  noticed,  even  after  heating  the 
dish,  the  dust  is  genuine.  As  "dust"  is  sometimes 
merely  copper  coated  with  gold,  the  better  plan  is  to 
cut  all  the  larger  grains  in  two,  so  that  the  acid  may 
attack  the  copper  should  it  be  present. 

Copper.  Copper  is  a  very  easy  mineral  to  test  for. 
First  crush  the  ore  and  dissolve  it  in  nitric  acid  by 
heating.  Then  dilute  with  some  water,  and  add  am- 
monia. The  solution  should  turn  dark  blue.  The  car- 
bonate ores  of  copper  do  not  extend  deep  in  the  mine. 
Their  places  are  taken  by  copper  pyrites.  Sulphide 
ores  are  usually  difficult  to  treat,  and  when  they  are  to 
be  tested  it  is  better  to  roast  them  before  trying  the 
tests  for  color. 

Test  for  copper  may  also  be  made  as  follows : 

The  sample  must  be  pulverized.  Take  an  ounce  of 
the  powder,  and  place  in  a  porcelain  cup.  Add  forty 
drops  of  nitric  acid,  twenty  drops  of  sulphuric  acid  and 
twelve  drops  of  hydrochloric  acid.  Boil  over  the  spirit 
lamp  until  white  fumes  arise.  When  cool,  mix  with 
a  little  water.  Filter  and  add  a  nail  or  two  to  the 
liquid.  The  copper  will  be  precipitated,  and  may  be 
gathered  up  and  weighed.  The  amount  of  copper  in 
the  sample  multiplied  by  32,000  will  be  the  copper  in  a 
ton  of  the  ore. 

Should  copper  be  suspected,  roast  the  powdered  ore 
and  mix  with  an  equal  quantity  of  salt  and  candle 
grease  or  other  fat;  then  cast  into  the  fire,  and  the 


60  ABC   OF   MINING. 

characteristic  flame  of  copper— first  blue  and  then 
green — will  appear.  This  test  is  better  made  at  night. 

Coal.  Coal  is  often  more  valuable  than  gold,  and 
the  prospector  should  be  prepared  to  estimate  the  value 
of  any  seams  he  may  come  across  during  his  travels. 
The  following  is  a  very  rough  but  wonderfully  effec- 
tive test  for  coal.  Take  a  clay  pipe,  pulverize  your 
sample,  weigh  off  twenty  pennyweights,  and  place  it 
in  the  bowl  of  the  pipe.  Make  a  cover  with  some  damp 
clay.  Dry  thoroughly,  and  put  the  bowl  upside  down 
over  a  flame.  The  gas  in  the  coal  will  come  out 
through  the  stem,  and  may  be  lit  with  a  match.  Let 
the  pipe  cool  after  the  gas  has  all  escaped,  break  off 
the  covering  of  clay,  and  if  the  coal  was  adapted  for 
coke  the  result  will  be  a  lump  of  that  substance  in  the 
bowl.  Weigh  this.  The  difference  in  weight  between 
the  coke  and  the  twenty  pennyweights  of  coal  that 
were  placed  in  the  bowl  will  represent  the  combustible 
matter  forced  out  by  the  heat.  Now  take  this  coke 
and  burn  it  on  a  porcelain  dish  over  the  lamp.  You 
will  have  more  or  less  asih  left,  and  the  difference  in 
weight  of  the  ash  and  the  coke  will  be  the  amount  of 
fixed  carbon  in  the  coal.  Your  test  is  complete,  and  it 
need  not  have  cost  you  even  the  pipe.  Sulphur  is  a 
detriment  to  coal,  and  if  you  notice  much  of  it  in  the 
escaping  fumes,  you  may  be  sure  your  sample  is  not 
worth  much. 

Mercury.  Cinnabar,  the  common  ore  of  mercury,  is 
a  sulphide.  Scratch  it  with  a  knife,  and  the  streak  will 
be  bright  crimson.  Dissolve  the  ore  in  nitric  acid,  add 
a  solution  of  caustic  potash,  and  you  have  a  yellow 


HOW  TO  TEST   FOR   MINERALS.  6l 

precipitate.  A  very  pretty  test  is  to  place  the  ore  pul- 
verized in  a  glass  tube  with  some  chloride  of  lime; 
close  the  top  of  the  tube,  and  place  a  smaller  one  there- 
in, so  bent  that  it  will  pass  into  a  basin  of  water ;  heat 
the  bottom  of  the  tube  containing  the  ore  and  lime, 
keeping  the  upper  part  and  the  small  tube  cold  with 
wet  rags,  and  you  will  have  a  deposit  of  quicksilver 
in  the  basin. 

Silver.  Silver  ore  may  be  detected  by  dissolving  a 
small  quantity  in  a  test  tube  with  a  few  drops  of  nitric 
acid.  Boil  until  all  the  red  fumes  disappear.  Let  the 
solution  cool,  and  add  a  little  water.  Filter  the  whole, 
and  add  a  few  drops  of  muriatic  acid,  which  will  pre- 
cipitate the  white  chloride  of  silver.  Dissolve  this 
precipitate  with  ammonia;  then  add  nitric  acid  once 
more.  Exposed  to  the  light,  the  precipitate  soon  shows 
a  violet  tint.  Pure  silver  is  the  brightest  of  metals,  of 
a  brilliant  white  hue,  with  rich  luster.  To  detect  chlo- 
ride of  silver  in  a  pulp,  rub  harshly  with  a  clean,  bright 
and  wet  copper  cartridge  or  coin,  and  if  there  be  sil- 
ver in  the  pulp  the  copper  will  be  coated  with  it. 
Graphite  will  also  whiten  copper,  but  the  film  is  easily 
rubbed  off. 

Nickel.  Nickel  may  be  determined  as  follows:  A 
little  of  the  powdered  ore  taken  up  on  the  point  of  a 
penknife,  and  dissolved  in  a  mixture  of  ten  drops  of 
nitric  and  five  drops  of  muriatic  acid,  should  be  boiled 
over  a  lamp  for  a  few  minutes,  and  ten  or  twelve  drops 
of  water  added.  A  small  quantity  of  ferro-cyanide  of 
potash  will  throw  down  a  whitish-green  precipitate,  in- 
dicating nickel. 


62  ABC   OF   MINING. 

Platinum.  Platinum  is  a  most  refractory  metal  to 
treat,  as  it  must  be  boiled  for  at  least  two  hours  in  the 
mixture  of  muriatic  and  nitric  acid,  known  as  aqua 
regia.  A  small  amount  of  alcohol  is  to  be  added  to 
the  solution,  and  the  latter  filtered.  The  platinum  is 
precipitated  with  ammonia  chloride. 

Manganese.  Manganese  may  be  proved  as  follows : 
A  few  grains  of  powdered  ore  are  placed  in  a  test-tube, 
with  three  or  four  drops  of  sulphuric  acid.  Two  or 
three  grains  of  granulated  lead  or  litharge  being 
dropped  in,  the  color  will  become  pink  should  man- 
ganese be  in  the  ore. 

A  preliminary  examination  of  a  mineral  may  be 
made  with  a  pocket  lens  and  a  penknife.  With  the 
first,  any  conspicuous  constituents  may  be  recognized, 
while  a  scratch  with  the  point  of  the  latter  will  give  an 
idea  as  to  the  softness  or  hardness  of  the  mineral. 
Should  much  quartz  (silica)  be  present,  a  sharp  blow 
with  the  steel  will  cause  sparks. 

The  next  test  should  be  with  some  ore  powdered 
artd  held  over  a  spirit  flame.  A  drop  or  two  of  water 
and  a  drop  of  sulpho-cyanide  of  potash  will  reveal  iron, 
should  such  be  present,  by  a  deep  red  coloration. 

To  another  portion  add  one  drop  of  hydrochloric 
acid,  and  a  dense,  curdy  precipitate  will  indicate  sil- 
ver, if  there  be  any. 

Added  to  the  same  original  nitric  acid  solution, 
several  drops  of  ammonia  water  would  detect  copper 
by  a  blue  color. 

Antimony,  tin,  aluminum,  zinc,  cobalt  and  nickel, 


HOW  TO  TEST  FOR   MINERALS.  63 

uranium  and  titanium  are  best  shown  by  the  blow- 
pipe. 

Carbonates,  that  is  those  minerals  that  contain  car- 
bon and  oxygen  in  addition  to  the  metal,  effervesce 
when  brought  into  contact  with  hydrochloric  acid. 
Some  sandstones  have  a  small  amount  of  lime  car- 
bonate, and  must  be  tried  under  the  lens,  as  the  bub- 
bles are  microscopic.  These  tests  are  extremely  use- 
ful, but  by  no  means  infallible,  owing  to  so  few  ores 
being  pure. 

When  the  explorer  wishes  to  know  all  the  constitu- 
ents of  the  ore  he  has  found,  he  must  analyze  it.  An 
analysis  gives  every  substance  in  the  ore.  Such  ex- 
aminations may  be  either  by  the  "dry"  or  "wet" 
methods,  though  usually  the  term  "analysis"  is  re- 
stricted to  the  latter,  and  "fire  assay"  is  used  to  describe 
the  former.  The  wet  assay  for  silver,  lead  or  mercury 
is  effected  as  follows: 

Drop  a  little  powdered  ore  in  a  test  tube ;  add  nitric 
acid;  dilute  with  ^  water;  warm  gently  over  the 
spirit  lamp.  It  may  dissolve  or  it  may  not.  In  the 
latter  case,  add  four  times  as  much  hydrochloric  acid. 
Should  all  these  attempts  fail,  a  fresh  sample  must  be 
taken,  and  equal  parts  of  sodium  carbonate  and  potas- 
sium carbonate  added,  and  the  whole  strongly  heated 
in  a  platinum  crucible.  The  contents,  after  cooling, 
is  dissolved  in  dilute  nitric  acid. 

In  any  case  the  assay  will  now  be  dissolved,  and  will 
be  in  the  solution.  Filter.  Pour  ten  drops  into  a  test 
tube;  add  three  or  four  drops  of  hydrochloric  acid.  A 
precipitate  appears.  It  may  be  silver,  lead  or  mer- 


64  ABC  OF   MINING. 

cury.  -  If  silver,  it  grows  dark  violet  after  exposure  to 
sunlight,  or  30  or  40  drops  of  ammonia  dissolves  it 
in  a  few  moments.  Should  it  not  dissolve,  it  is  lead  or 
mercury.  Test  for  lead  by  filtering,  and  heating  some 
of  the  precipitate  on  charcoal  before  the  blow-pipe.  A 
bead  and  yellow  incrustation  indicate  lead.  Should 
none  of  these  things  happen,  then  the  metal  is  mercury. 
Filter;  place  in  glass  tubes;  heat  gently,  and  a  mirror 
of  quicksilver  will  appear  on  the  sides  of  the  glass. 

This  is  as  far  as  the  prospector,  without  the  various 
reagents  and  chemicals  that  the  analyist  has  always  at 
hand,  will  be  able  to  go.  More  complex  treatment 
must  be  reserved  until  a  return  to  civilization. 


BLOW-PIPE   TESTS.  65 


CHAPTER   III. 
BLOW-PIPE   TESTS. 


BLOW  PIPE. 

As  a  means  of  readily  detecting  the  presence  of  min- 
erals in  their  ores  the  blow-pipe,  in  the  hands  of  a 
skillful  operator,  is  unrivaled.  Nor  is  this  skill  at  all 
hard  to  come  by;  two  or  three  weeks'  patient  study 
under  a  good  master  should  teach  a  great  deal,  and 
subsequently  proficiency  would  come  by  practice  in 
the  field.  Unfortunately,  some  very  clever  men  have 
become  so  enthusiastic  as  to  blow-pipe  work  that  they 
have  devised  methods  by  which  the  amount  of  metal 
in  an  ore  as  well  as  its  nature  may  be  determined,  but 
in  so  doing  have  so  enlarged  the  amount  of  apparatus, 
and  complicated  the  tests  so  seriously  that  the  sim- 
plicity of  the  blow-pipe  outfit  is  in  danger  of  being 
lost,  and  its  chief  advantage  of  being  forgotten;  for 
there  are  many  better  ways  of  determining  the  value 
of  an  ore.  A  good  assay  or,  better  still,  a  mill  run,  is 
worth  incomparably  more  than  any  quantitative  blow- 
pipe test,  even  when  conducted  by  a  Plattner.  . 

The  chemical  blow-pipe  is  made  of  brass  or  German 
silver,  with  platinum  tip. 

5 


66 


ABC   OF  MINING. 


The  best  fuel,  taking  everything  into  consideration, 
is  a  paraffin  candle  in  cold  climates,  and  a  stearine  can- 
dle in  hot  ones.  Tallow  may  do  in  an  emergency,  but 
it  requires  too  much  snuffing. 

The  blow-pipe  can  produce  two  flames.    The  one 


REDUCING  FLAME. 

known  as  the  reducing  flame,  and  generally  printed 
as  R.  F.;  and  the  oxidizing  flame,  represented  by  the 
initials  O.  F.  In  the  first  the  substance  under  exam- 


OXIDIZING    FLAME. 

ination  is  heated  out  of  contact  with  the  air  and  parts 
with  its  oxygen.  In  the  second,  it  is  heated  in  the  air 
and  absorbs  oxygen. 

Well-burnt  pine  or  willow  charcoal  in  slabs  3  inches 
by  if  inches  is  the  material  upon  which  the  mineral 


BLOW-PIPE  TESTS.  67 

to  be  tested  is  placed.  A  small  shallow  depression  is 
scraped  out  of  one  side  of  it  and  the  assay  placed 
therein. 

Platinum  wire,  some  3  inches  long,  conveniently 
fused  into  a  piece  of  glass  tube  as  a  handle,  is  used 
to  test  the  coloration  of  minerals  in  the  flame.  This 
should  be  cleaned  occasionally  in  dilute  sulphuric  acid 
and  then  washed  in  water. 

A  small  pair  of  forceps  with  platinum  points  serve 
a  great  variety  of  purposes,  but  the  beginner  must  be 
careful  not  to  heat  metallic  substances  in  them  to  a 


AGATE   MORTAR. 

red  heat,  as  he  may  thereby  cause  an  alloy  of  the  metal 
with  the  platinum  and  spoil  them  for  future  use. 

Glass  tubing  one-twelfth  to  one-quarter  inch  in 
diameter  and  from  four  to  six  inches  in  length  is 
used  for  a  variety  of  purposes.  From  this  material 
what  are  known  as  closed  tubes  may  be  made  by 
heating  a  piece  of  the  tubing  at  or  about  its  center 
over  a  spirit  lamp,  and,  when  the  glass  has  fused,  pull- 
ing it  apart.  These  closed  tubes  are  used  in  heating 
substances  out  of  contact  with  the  air. 

A  small  agate  mortar  is  indispensable.    It  must  be 


68 


ABC   OF   MINING. 


used  for  grinding  substances  softer  than  itself  to  a 
powder,  but  it  will  break  if  rapped  sharply. 

A  small  jeweler's  hammer  is  used  to  flatten  metallic 
globules  upon  any  hard  surface  A  regular  blow-pipe 
outfit  would  include  a  small  anvil  for  this  purpose, 
but  it  is  hardly  necessary,  as  any  iron  or  steel  surface 
will  do. 

A  magnet  will  detect  the  presence  of  any  magnetic 


MAGNET. 


LENS. 


OF 
TEST  TUBES. 


mineral,  especially  if  it  is  reduced  to  powder  and  the 
test  made  under  water. 

Two  small  files,  one  three-cornered  and  the  other 
rat-tailed,  must  be  included  in  the  list  of  requisites. 
By  means  of  the  former,  glass  tubing  may  be  notched 
and  pulled  or  pushed  apart,  and  the  latter  is  necessary 
in  fitting  glass  tubing  to  the  cork  of  wash-bottles  and 
other  apparatus. 

A  good  lens  is  indispensable.  That  known  as  the 
Coddington  is  as  good  as  any. 


BLOW-PIPE   TESTS.  69 

A  dozen  test  tubes  of  hard  glass,  with  stand,  in 
small  and  medium  sizes,  should  not  be  forgotten. 

A  glass  funnel  2^  inches  in  diameter  is  requisite  in 
filtering.  The  circular  filter  papers  are  folded  in  four 
and  placed  in  the  funnel,  point  down,  three  thicknesses 
of  the  paper  being  on  one  side  of  the  funnel  and  one 
thickness  on  the  other. 

A  wash-bottle  is  made  from  a  flask  into  which  a 
sound  cork  has  been  placed  with  holes  in  it  for  two 
pieces  of  glass  tubing.  The  one  serves  as  a  mouth- 
piece into  which  the  operator  blows,  while  the  other, 
reaching  almost  to  the  bottom  of  the  bottle  and  end- 
ing in  a  spout  outside  the  cork,  permits  a  stream  of 
water  to  be  forced  out  of  the  bottle  when  it  is  blown 
into. 

A  few  glass  rods  in  short  lengths  do  for  stirrers.  A 
little  ingenuity  is  better  than  much  apparatus. 

Of  reagents,  all  those  to  be  found  in  a  well-ap- 
pointed laboratory  may  occasionally  be  of  service,  but 
the  rough  and  ready  prospector  can  get  along  fairly 
well  with  the  following:  Carbonate  of  soda,  borax, 
microcosmic  salt,  cobalt  solution,  cyanide  of  potassium, 
lead  granulated,  bone  ash,  test  papers  of  blue  litmus 
and  turmeric,  the  former  for  proving  the  presence  of 
acid  in  a  solution  and  the  latter  that  of  an  alkali. 

The  foregoing  are  all  dry  reagents.  Among  the 
wet  reagents  are :  Water — clean  rainwater — or,  better 
still,  distilled  water;  hydrochloric  acid,  sulphuric  acid, 
nitric  acid,  ammonia,  nitrate  of  cobalt. 

Heating  a  mineral  with  carbonate  of  soda  on  char- 
coal is  accomplished  as  follows:  The  pulverized  min- 


ABC   OF   MINING. 


eral,  intimately  mixed  with  three  times  its  bulk  of  car- 
bonate of  soda,  is  placed  in  the  cavity  on  the  coal.  Tin 
ore,  which  is  very  difficult  to  reduce,  should  have  a 
fragment  of  cyanide  of  potassium  placed  upon  it  after 
it  has  been  heated  for  a  few  seconds,  and  the  flame  is 
then  reapplied.  A  globule  of  metal  should  result,  and 
perhaps  an  incrustation  on  the  coal.  The  reaction  is 
as  follows: 

Incrustation. 
None. 
None. 
None. 
Red  when  hot,  yellow 

when  cold. 
Red  when  hot,  yellow 

when  cold. 
Yellow  when  hot,white 

when  cold. 
Antimony. White,  brittle,  fumes.  White. 

A  small  loop  is  made  at  the  end  of  the  platinum  wire, 
and  it  is  heated  and  dipped  in  borax;  heated  again, 
then  touched  while  hot  to  the  powdered  mineral  and 
heated  once  more.  The  following  colors  are  obtained: 


Metal. 
Gold. 
Silver. 
Copper. 
Lead. 

Globule. 
Yellow,  malleable. 
White,  malleable. 
Red,  malleable. 
White,  malleable. 

Bismuth. 

White,  brittle. 

Zinc. 

None. 

COLOR 

O.  F. 

Red  or  yellow,  hot. 
Yellow  or  colorless,  cold 
Blue,  hot  or  cold. 
Green,  hot ;  blue,  cold. 
Amethyst. 
Green. 
Violet,  hot;  red-brown, 


OF    BEAD. 

R.  F. 
Bottle-green. 

Blue. 

Red. 

Colorless. 

Green. 

Gray. 


Metal. 
Iron. 

Cobalt. 

Copper. 

Manganese. 

Chromium. 

Nickel. 


BLOW-PIPE  TESTS.  71 

The  substance  to  be  tested  is  generally  powdered 
and  moistened,  placed  in  the  cavity  and  covered  or 
not  as  circumstances  may  demand,  with  a  pinch  of  car- 
bonate of  soda  or  other  suitable  reagent.  The  follow- 
ing results  may  be  obtained: 

Antimony.  Place  the  mineral  in  the  cavity  with  a 
little  of  carbonate  of  soda,  and  blow  upon  it  with  the 
inner  or  oxidizing  flame.  This  is  formed  by  insert- 
ing the  blow-pipe  an  eighth  of  an  inch  into  the  flame 
and  blowing  steadily.  A  white  incrustation  on  the 
coal,  and  a  brittle  button  of  antimony  should  be  the 
result. 

Lead.  Treat  the  suspected  lead  ore  the  same  way, 
and  you  will  get  a  yellow  incrustation  on  the  coal  and 
a  button  of  malleable  lead. 

Zinc.  Proceed  as  above,  and  after  blowing  for  a 
few  seconds  moisten  the  incrustation  with  a  drop  of 
nitrate  of  cobalt.  Heat  once  more,  but  this  time  use 
the  outer  or  reducing  flame,  which  is  produced  by 
keeping  the  point  of  the  blow-pipe  a  little  outside  the 
flame  and  blowing  more  gently  than  before,  so  that 
the  whole  flame  playing  upon  the  coal  may  be  yellow 
in  color.  A  green  incrustation  will  be  an  evidence  of 
zinc. 

Copper.  As  usual,  mix  the  ore  and  the  soda  into  a 
paste  and  fuse  it  with  the  oxidizing  flame.  Dig  the 
mass  out  of  the  charcoal  with  the  point  of  a  knife  and 
rub  it  in  the  mortar  with  water.  Now  decant  into  a 
test  tube,  and,  allowing  the  sediment  to  settle,  pour 
off  the  water.  If  there  was  copper  in  the  ore,  red 
scales  will  be  found  in  the  test  tube. 


72  ABC   OF   MINING. 

Arsenic.  Heat  in  the  inner  flame  for  a  second  or 
two,  and  if  the  ore  contains  arsenic  you  will  notice  an 
odor  of  garlic. 

Tin.  This  is  a  very  difficult  ore  to  reduce,  but  the 
addition  of  a  little  cyanide  of  potas'h  to  the  powdered 
ore  will  make  it  easier.  Fuse,  after  moistening  on  the 
charcoal,  in  the  oxidizing  flame,  and  you  will  prob- 
ably obtain  small  globules  of  tin. 

Silver.  Make  a  paste  of  the  ore  with  carbonate  of 
soda;  add  a  small  piece  of  lead  and  fuse  into  a  button. 
Make  a  second  paste  of  bone  ash  and  water,  and  after 
you  have  dried  it  with  a  gentle  flame  place  the  button 
of  silver  and  lead  on  the  bone  ash,  and  turn  on  the 
oxidizing  flame.  The  lead  will  disappear,  leaving  a 
silver  globule.  Should  it  not  be  pure  white,  but  more 
or  less  tinged  with  yellow,  it  probably  contains  gold; 
and  if  the  button  be  dissolved  in  nitric  acid,  whatever 
remains  behind  is  gold. 

Sometimes  it  is  desirable  to  determine  whether  tellu- 
rium is  present  in  an  ore.  This  is  very  easy  to  find  out. 
All  that  is  required  is  a  blow-pipe,  alcohol  lamp  and 
a  porcelain  dish.  Break  off  a  small  piece  of  the  ore, 
place  it  in  the  dish  previously  warmed,  blow  upon 
the  ore  with  the  blow-pipe  until  it  is  oxidized,  then 
drop  a  little  sulphuric  acid  on  the  ore  and  dish.  If 
tellurium  be  present,  carmine  and  purple  colors  on  the 
assay  will  proclaim  the  fact. 

Bismuth  ores  are  very  heavy;  usually  they  have 
more  or  less  antimony  associated  with  them,  which 
is  a  drawback,  as  the  separation  is  an  expensive  mat- 
ter and  the  returns  are  less  than  they  would  be  from  a 


BLOW-PIPE   TESTS.  73 

low  grade  pure  ore.  In  testing  for  this  metal,  dissolve 
a  crushed  sample  in  nitric  acid  and  then  add  potash  in 
excess.  If  the  ore  is  one  containing  bismuth,  you 
should  have  a  white  precipitate;  if  it  contains  cobalt, 
you  will  get  a  bluish-green  coloration.  Bismuth  is 
worth  about  fifty  cents  a  pound  if  pure  and  free  from 
antimony. 

Galena  is  often  mistaken  for  other  ores,  specular 
iron  ore  for  instance.  If  the  ore  be  crushed  and  heated 
in  nitric  acid  until  dissolved,  some  water  added,  and 
an  addition  made  to  the  solution  of  a  few  drops  of 
ferrocyanide  of  potassium,  a  dark  blood-red  precipitate 
is  thrown  down.  If  the  ore  were  galena,  there  would 
be  no  coloration.  The  so-called  steel  galena  which 
carries  a  little  zinc  is  generally  richer  in  silver  than 
the  ordinary  cube  galena,  though  the  reverse  is  some- 
times the  case. 

If  lead  ore  be  dissolved  in  nitric  acid,  the  solution 
diluted,  and  some  hydrochloric  acid  added,  a  white 
precipitate  is  thrown  down.  Add  ammonia  and  the 
precipitate  remains  unaltered. 

The  blow-pipe  operator  has  to  learn  to  breathe  and 
blow  at  the  same  time;  the  breathing  he  does  through 
the  nostrils,  the  blowing  is  produced  by  the  natural 
tendency  of  the  cheeks  to  collapse  when  distended  with 
air.  A  skillful  operator  can  blow  for  many  minutes 
at  a  time  without  the  slightest  fatigue. 

To  identify  cinnabar,  the  ore  from  which  quicksilver 
is  obtained,  make  a  paste  of  the  substance  in  powder 
and  carbonate  of  soda.  Heat  in  the  open  tube,  and  a 
globule  of  mercury  will  result, 


74  ABC   OF   MINING. 

Sulphur  turns  silver  black.  Make  a  paste  with  car- 
bonate of  soda,  heat  on  the  charcoal,  and  removing 
the  mass  with  the  point  of  a  knife  lay  it  on  a  silver 
coin  and  moisten.  A  black  sulphide  of  silver  should 
show  quickly  on  the  coin  if  sulphur  is  present.  Mag- 
nesia gives  a  faint  pink  color  when  'heated  and  treated 
with  nitrate  of  cobalt  on  coal.  Alumina  under  the 
same  circumstances  give  a  blue  color. 

Roasting  is  an  oxidizing  process,  the  substance  be- 
ing heated  in  air,  so  that  it  may  absorb  oxygen. 

The  test  by  reduction  with  soda  on  coal  in  the  R.  F. 
is  particularly  valuable  in  the  case  of  copper  ore,  as 
little  as  i  per  cent,  being  detected. 


ECONOMIC  ORES  AND  MINERALS.          75 


CHAPTER    IV. 
ECONOMIC  ORES  AND  MINERALS. 

Aluminum  is  derived  from  two  ores,  cryolite  and 
bauxite.  This  metal  has  made  rapid  strides  into  favor 
during  the  past  half-dozen  years.  Although  known 
since  1827,  it  remained  a  rare  substance  in  the  metallic 
form,  though  it  is  the  most  abundant  of  any  of  the 
metals  in  its  ore.  In  ordinary  clay  there  is  an  inex- 
haustible source  of  aluminum.  But  the  ores  that  yield 
the  metal  cheaply  are  few.  Until  recently,  cryolite, 
found  abundantly  in  Greenland,  was  the  chief  source 
of  the  metal,  but  now  bauxite  is  used  in  its  place. 
Bauxite  is  a  limonite  iron  ore  in  which  a  part  of  the 
iron  has  been  replaced  by  aluminum.  It  is  found  in 
Alabama,  Georgia  and  Arkansas,  as  well  as  in  Europe. 
Aluminum  is  white,  and  very  light  in  weight.  It  does 
not  tarnish  easily. 

The  chemical  composition  of  these  ores  is: 

Aluminum. 

Cryolite,  Al2F6.6NaF 12.8  per  cent. 

Bauxite,  A12O3.3H2O 73.9  per  cent. 

In  1895  the  production  of  this  metal  in  the  United 
States  was  900,000  pounds.  In  1899  ^  rose  to  6,500,- 
ooo  pounds.  The  only  firm  producing  aluminum  is 
the  Pittsburg  Manufacturing  Company  of  Buffalo,  N. 
Yv  who  reduce  the  metal  from  bauxite,  which  they 


76  ABC   OF   MINING. 

obtain  in  the  southern  states.  One  of  the  latest  uses  for 
this  metal  is  for  gold  miners'  pans.  The  French  seem 
to  keep  ahead  of  the  rest  of  the  world  in  finding  new 
uses  for  aluminum. 

Most  of  the  supply  of  cryolite  comes  from  "Green- 
land, where  it  occurs  in  veins  running  through  gneiss 
rocks.  Glass-makers  use  it  and  pay  good  prices  for  it. 
Lately  makers  of  aluminum  also  buy  it,  as  it  contains 
13  per  cent,  of  that  metal. 

A  new  aluminum-bearing  mineral, discovered  in  New 
Mexico  and  in  Ohio,  is  called  native  alum.  It  gives 
50.16  per  cent,  alumina,  and  may  be  treated  by  solu- 
tion in  warm  water,  filtration,  evaporation  and  roast- 
ing. No  estimate  has  yet  been  made  of  the  amount 
available. 

As  bauxite  promises  to  be  in  greater  demand  in  the 
future  than  in  the  present,  owing  to  the  ever-increasing 
demand  for  aluminum,  the  prospector  will  do  well  to 
make  himself  thoroughly  familiar  with  its  appearance. 
It  is  creamy  white  when  free  from  iron,  and  the  grains 
are  like  little  peas,  or  pisolitic.  It  contains  water,  alu- 
minum, silica,  and  generally  iron.  The  French  beds 
near  the  town  of  Baux  are  30  miles  long  and  40  feet 
thick.  In  the  United  States,  beds  have  been  found  in 
Alabama,  Georgia  and  Arkansas.  The  Georgia  beds 
are  turning  out  three-fifths  of  the  bauxite  produced 
in  America.  The  ore  is  in  beds  and  pockets,  and 
enough  has  been  prospected  to  assure  a  supply  for 
some  years  to  come,  unless  the  demand  should  grow 
very  decidedly,  in  which  case  a  scarcity  might  soon  be 
felt.  The  American  ore  is  easier  to  work  than  the 


ECONOMIC  ORES  AND  MINERALS.  77 

French,  and  manufacturers  prefer  it  to  any  they  can 
import,  even  though  the  cost  is  higher  and  the  per- 
centage of  aluminum  smaller.  The  Arkansas  deposits 
are  as  thick  as  the  French,  and  only  300  feet  above 
the  level  of  the  tide.  Imported  bauxite  cost  $5  to  $7 
a  ton  in  New  York  City.  American  ore  costs  $5  to 
$12  a  long  ton.  Best  selected  Georgia  brings  $10. 

Should  the  deposits  of  bauxite  give  out,  the  manu- 
facturers of  aluminum  would  probably  fall  back  on 
cryolite.  At  Tvigtuk,  on  the  west  coast  of  Greenland, 
it  exists,  as  a  very  heavy  vein,  in  gneiss.  It  is  semi- 
transparent,  and  snow-white.  Impurities  may  stain  it 
yellow  or  red  or  even  black.  Its  specific  gravity  is 
2.95,  and  its  hardness  2.5  to  3.  It  is  fusible  in  the 
flame  of  a  candle,  and  yields  hydrofluoric  acid  if 
treated  with  sulphuric  acid.  It  is  still  used  for  making 
soda  and  aluminum  salts,  and  an  imitation  porcelain. 
It  is  also  in  general  use  as  a  flux. 

Amber.  This  is  a  fossil  resin,  or  gum,  and  may  often 
be  found  in  lignite  beds.  Recent  discoveries  have  been 
made  on  the  coast  of  British  Columbia  that  are  ex- 
pected to  supply  the  world.  All  pipe-smokers  know 
it. 

Antimony.  The  commercial  ore  of  this  metal  is  the 
sulphide  known  as  stibnite,  or  gray  antimony.  Its 
composition  when  pure  is  72  per  cent,  antimony  and 
28  per  cent,  sulphur.  Hardness  is  2;  gravity,  4.5; 
luster,  metallic;  opaque;  gray;  cleavage,  perfect. 
Fracture,  conchoidal.  Texture,  granular  to  massive. 
The  ore  tarnishes  quickly,  is  easily  melted,  or  dis- 
solved in  hydrochloric  acid.  The  associated  minerals 


78  ABC  OF  MINING. 

are  generally  the  ores  of  lead,  zinc,  and  carbonate  of 
iron.  Baryta  may  be  the  gangue  or  veinstone.  Anti- 
mony is  worth  from  10  to  15  cents  a  pound. 

Although  antimony  occurs  in  many  minerals,  the 
only  commercial  source  is  the  sulphide,  stibnite.  An- 
timony is  used  as  an  alloy  in  type  metal,  pewter,  and 
babbitt  metals.  It  is  injurious  to  copper,  even  one- 
tenth  of  one  per  cent,  reducing  the  value  of  that  metal 
very  considerably.  The  price  varies  greatly,,  being  now 
about  10  cents  a  pound. 

The  composition  of  stibnite  is: 

Antimony. 
Stibnite,  Sb2S3 71 .8  per  cent 

The  production  of  antimony  in  this  country  is  not 
very  large.  The  output  of  1899  was  but  1,250  tons, 
valued  at  $241,250.  The  ore  is  worth  from  $40  to  $50 
a  ton  delivered  at  Staten  Island,  N.  Y. 

Apatite  suffered  in  demand  when  the  cheap  phos- 
phates of  South  Carolina  were  discovered,  and  these 
in  turn  are  being  ousted  from  the  markets  of  the  world 
by  Thomas  slag,  an  artificial  phosphate,  and  by  the 
easily-mined  natural  phosphates  of  Algeria.  The 
price  varies  with  the  quality  of  the  rock,  from  $1.75 
to  $i  i  per  ton,  averaging  in  1899,  $3.86. 

Apatite  is  a  phosphate  of  lime,  containing  43  per 
cent,  of  phosphoric  acid.  It  occurs  in  the  old  crystal- 
line and  primary  rocks  of  Canada,  but  although  still 
of  some  value  it  has  yielded  the  position  it  once  occu- 
pied to  the  Carolina  phosphate  deposits,  which,  al- 
though not  so  rich  in  acid,  are  softer,  and  less  ex- 


ECONOMIC  ORES  AND  MINERALS.          79 

pensive  to  utilize.  Apatite  is  doubtless  derived  from 
the  remains  of  animals  or  fishes  that  lived  in  the  dis- 
tant past.  The  colors  are  often  beautiful — green,  pink, 
gray,  etc. — but  the  sheen  is  always  white.  Hardness 
of  4.8.  Specific  gravity,  3.1. 

Asbestos.  This  fibrous  silicate  of  magnesia  and 
lime  is  to  be  looked  for  among  primary  rocks  near 
serpentine  dike.  The  fibers  of  this  material  may  be 
woven  into  cloth  that  will  be  fire-proof.  It  is  of  con- 
siderable, though  fluctuating,  value. 

The  demand  for  this  material  is  likely  to  in- 
crease, though  at  present  the  supply  is  fully  equal  to 
demand.  It  is  being  used  in  Germany  to  make  fire- 
proof paper,  and  in  Quebec  to  make  asbestos  plaster 
for  covering  wood-work.  It  is  generally  quarried  in 
open  pits,  the  rock  being  crushed  in  a  rock-breaker, 
and  the  fiber  freed  from  adhering  particles  of  rock  and 
dust.  It  is  then  sorted,  the  longest  fibers  going  into 
the  first  quality  heap.  The  production  in  1899  in 
the  United  States  was  912  tons,  value  $13,860;  in 
Canada,  23,266  tons,  value  $598,736. 

Borax.  This  mineral  is  borate  of  soda.  Its  compo- 
sition is:  37  per  cent,  boric  acid,  16  per  cent,  soda, 
and  47  per  cent,  water.  Its  gravity  is  1.7.  Hardness, 
2.3.  It  is  white,  and  has  a  sweetish  taste.  Borax  is 
valuable,  but  occurring  as  it  does  as  an  incrustation 
upon  the  ground  over  large  areas,  a  detailed  descrip- 
tion would  be  superfluous,  as  the  explorer  will  surely 
recognize  it  should  he  find  it. 

Clay.  A  good  bed  of  clay  may  be  of  value  in  an 
accessible  region.  Brick-clay  contains  silica,  alumina, 


8o  ABC   OF   MINING. 

iron,  etc.  Potters'  clay  is  made  by  suspending  ordin- 
ary brick-clay  in  water,  and  running  off  the  water  and 
fine  particles  suspended  therein.  These  are  allowed  to 
settle,  and,  when  dry,  are  fine  potters'  clay.  The  better 
the  clay,  the  larger  the  percentage  of  potters'  clay. 
Fire-clay  should  contain  60  per  cent,  of  silica,  and  30 
per  cent  of  alumina.  Mixed  with  sand  and  burnt  into 
bricks,  it  will  resist  great  heat.  Light-colored  clays 
are  preferable  for  this  purpose,  as  iron  is  prejudicial 
to  a  good  fire-brick/  Kaolin  is  the  finest  porcelain 
clay,  and  the  best  comes  from  China,  Japan  or  France. 
It  is  a  product  of  decay  in  feldspar  rocks.  The  potash 
is  washed  out,  and  the  silica  and  alumina  left  as  parts 
of  a  white  clay  of  fine  grain. 

Coal.  Anthracite  is  bituminous  coal  that  has  been 
subjected  to  great  heat  and  pressure;  in  plain  lan- 
guage, baked.  It  contains  over  90  per  cent,  of  carbon. 
Specific  gravity  1.5  to  1.8.  Hardness,  2.3  to  2.6.  The 
ash  left  after  burning  is  white  or  red.  There  is  little 
or  no  sulphur  in  anthracite.  It  does  not  coke. 

There  are  three  main  divisions  of  coal,  arranged 
according  to  their  carbon,  water  and  ash.  They  are: 

Carbon.  Water.  Ash. 

Anthracite 80 — 95  p.  c.  2 — 3  p.  c.  4 — 10  p.  c. 

Bituminous.  .  .45 — 80  p.  c.  I — 5  p.  c.  8 — 20  p.  c. 

Lignite 7 — 45  p.  c.  15 — 36  p.  c.  6 — 40  p.  c. 

Good  bituminous  coal  contains  about  85  per  cent,  of 
carbon,  but  the  composition  varies  greatly.  Cannel 
coal  is  a  variety  of  bituminous  that  gives  off  much 
gas.  It  burns  with  a  bright  flame  in  an  open  grate, 


ECONOMIC  ORES  AND  MINERALS.  8l 

igniting  as  easily  as  a  candle.  Lignite  is  intermediate 
between  coal  and  peat.  All  the  Rocky  Mountain  coals 
are  lignites.  It  is  a  very  inferior  coal  at  its  worst, 
while  at  its  best  it  is  nearly  the  equal  of  a  poor  bitu- 
minous coal. 

Some  coals  will  coke  and  others  will  not;  nothing 
but  a  trial  can  settle  this  matter  in  each  individual  case. 
Good  coking  coal  is  very  valuable. 

Cobalt.  Cobalt  ores  are  always  found  in  veins  with 
other  metals.  Pure  cobalt  is  extremely  rare.  Cobalt 
colors  are  used  for  porcelain  painting,  glass-staining, 
etc. 

Chromium.  All  chrome  is  obtained  from  chromite, 
which  contains  68  per  cent,  of  chrome  sesqui-oxide, 
the  remainder  being  iron  protoxide.  Hardness,  5.5; 
gravity,  4.4 ;  luster,  sub-metallic ;  opaque.  Steel-gray 
to  almost  black.  Harsh.  Brittle.  Cleavage,  imper- 
fect. Fracture,  uneven.  Texture,  massive  to  granular. 
Chromite  in  gravel  looks  like  shot.  Serpentine  often 
contains  it,  when  it  is  apt  to  resemble  a  fine-grained 
magnetite.  It  is  used  chiefly  in  iron  and  steel  alloys, 
and  in  making  armor  plate.  It  is  also  used  in  dyeing 
fabrics  and  in  paint  manufacture.  But  little  chrome 
ore  is  produced  in  the  United  States.  The  importa- 
tion in  1899  was  J5>793  tons>  value  $18.03  Per  ton' 

Chromite,  FeOCr2O3 47-68 

This  ore  is  merchantable  at  $22  to  $25  per  ton. 
Domestic  ore  ranges  from  $10  to  $12  a  ton,  while 
the  pure  imported  ores  are  worth  $21  a  ton.     The 


82  ABC   OF   MINING. 

yearly  consumption  in  the  United  States  is  about  16,- 
ooo  tons,  and  the  American  production  100  tons.  This 
ore  is  useful  as  a  lining  for  furnaces,  and  the  demand 
promises  to  become  important.  Newfoundland  is  said 
to  contain  large  deposits. 

Copper.  Native  copper  occurs  in  the  Lake  Superior 
region, but  the  demands  of  commerce  are  supplied  from 
chalcopyrite  or  copper  pyrites,  and  tetrahedrite  or  gray 
copper  ore.  Many  different  ores  of  copper  may  exist 
in  the  same  vein.  On  the  surface  an  iron  cap  of  gossan 
reveals  the  deposit;  immediately  below  may  be  black 
oxide  of  copper  with  some  malachite,  lower  down  red 
oxide,  and  below  the  water-line  copper  sulphides.  The 
following  are  the  principal  copper  ores: 

Sp.  Gravity.  Hardness.  P.  C.  Cu. 

Native  copper  8.8                2.8  100 

Chalcopyrite  4.2                3.7  35 

Enargite  4.4                3.0  48 

Tetrahedite  5.0  3.5104.5  35 

Chalcocite  5.6                2.7  80 

Bornite  5.0                3.0  55 

Melaconite  6.2  2.0  to  3.0  80 

Cuprite  6.0                3.6  89 

Chrysocolla  2.2                3.0  45 

The  common  ore  is  native  copper,  often  associated 
with  native  silver,  the  two  remaining,  chemically,  quite 
distinct.  Some  masses  of  copper  occur  that  are  too 
large  to  handle  and  must  be  cut  by  cold  chisels,  a 
method  that  costs  more  for  labor  than  the  value  of  the 
metal.  The  Lake  Superior  mines  produce  140,000,000 
pounds  of  copper  a  year,  while  those  of  Montana  made 


ECONOMIC  ORES  AND  MINERALS.          83 

the  gigantic  output  of  228,000,000  pounds  in  1896. 
The  great  Anaconda  mine,  of  Butte,  is  the  heaviest 
producer,  yielding  more  than  half  the  state's  total. 

During  1899  the  New  York  copper  market  rate 
varied  between  14.75  cents  and  18.46  cents  per  pound. 
Copper  is  probably  abundant  in  the  shape  of  pyrites 
in  many  parts  of  Canada,  especially  in  the  Northwest, 
and  prospectors  in  that  region  should  search  diligently 
for  it.  The  Lake  Superior  mines  are  unique  in  being 
deposits  of  native  copper. 

Owing  to  the  great  demand  for  copper  following 
upon  the  extraordinary  spread  of  electricity,  copper 
properties  have  become  so  enormously  valuable  that, 
possibly,  the  explorer  will  be  quite  as  fortunate  in  find- 
ing copper  as  in  finding  gold.  Moreover,  with  the  ex- 
ception of  Spain  and  Chili,  the  United  States  has  no 
serious  rivals  in  copper  production, — Montana  and 
Michigan,  producing  the  greater  part  of  the  output. 
The  famous  Calumet  and  Hecla  mine,  in  Michigan,  is 
now  down  4,000  feet  and  still  yields  ore.  The  most 
copper  ores  are  not  difficult  to  distinguish.  Every  one 
is  familiar  with  the  ruddy  hue  of  pure  copper,  the  color 
of  the  native  metal.  It  may  be  flattened  under  the 
hammer  or  cut  with  the  knife.  A  little  of  the  ore 
mixed  with  grease  colors  a  flame  green.  Copper  ores 
are  heavy,  and  generally  of  a  bright  color,  either  red, 
blue,  green,  yellow  or  brown. 

Corundum.  Nine  hundred  and  seventy  tons  of  this 
abrasive  were  produced  in  the  United  States  in  1899; 
value,  $78,570.  Corundum  is  found  in  feldspar  veins, 
and  associated  with  chlorites  in  serpentine  rock.  North 


84  ABC   OF   MINING. 

Carolina  furnishes  half  the  corundum  marketed.  The 
presence  of  this  substance  is  always  indicated  in  the 
South  by  serpentine,  chrysolite,  or  olivine  rocks;  ex- 
perience being  the  only  guide  the  miners  have  in  find- 
ing new  deposits.  The  contacts  of  the  olivine  rocks 
with  gneiss  usually  produce  rich  deposits.  Corundum 
is  the  hardest  substance  known,  next  to  the  diamond. 
It  is  used  as  a  polishing  powder.  Emery  is  an 
impure  corundum  containing  iron.  Corundum  is 
composed  of  53  per  cent  aluminum  and  47  per  cent 
oxygen.  Specific  gravity  is  4.  Hardness,  9. 

Feldspar.  The  Maine,  Pennsylvania,  New  York, 
and  Connecticut  ores  are  worth  $3  to  $6  per  long 
ton  (2,240  pounds)  at  point  of  production. 

Fluorspar.  The  American  market  is  supplied  by 
ore  from  Rosiclare,  111.,  Marion,  Ky.,  Hardin  Co.,  111., 
and  Liumpton  Co.,  Ky.,  and  imported  spar.  It  is 
worth  $6  a  ton  of  2,000  pounds.  This  spar  is  softer 
than  quartz  and  of  most  brilliant  colors,  varying 
through  the  yellows,  greens,  blues  and  reds,  to  pure 
white.  The  streak  is  always  white.  Specific  gravity, 
3.  Hardness,  4.  It  is  worth  mining  when  abundant 
and  accessible. 

Gems.  Gems  are  to  be  looked  for  in  a  country  of 
crystalline  rock,  such  as  granite,  gneiss,  dolomite,  etc. 
Topaz  and  ruby  are  generally  discovered  in  crystalline 
limestones,  while  turquoise  is  usually  found  in  clay 
slate.  It  is  not  likely  that  the  American  prospector 
will  come  upon  the  true  oriental  ruby;  he  will  more 
probably  find  the  garnet.  The  ruby  is  next  to  the 
diamond  in  hardness  and  in  value,  and  consists  prac- 
tically of  pure  alumina.  The  garnet  is  but  as  hard 


ECONOMIC  ORES  AND  MINERALS  85 

as  quartz,  and  is  a  silicate  of  alumina  with  lime  and 
a  little  iron.  They  crystallize  in  different  systems,  the 
more  valuable  gem  belonging  to  the  rhombohedral, 
and  the  less  valuable  to  the  isometric  system. 

The  turquoise  which  has  lately  been  found  in  Ari- 
zona is  not  a  crystal.  The  blue  color  which  distin- 
guishes it  is  derived  from  copper.  It  is  a  phosphate 
of  alumina  with  water  in  composition.  In  form  it  is 
kidney  shaped  or  stalactitic.  Lazulite,  a  far  less  valu- 
able substance,  is  also  blue,  but  as  it  crystallizes  in 
the  monoclinic  system  it  should  not  be  mistaken  for 
turquoise.  Moreover,  lazulite  is  softer  and  contains 
magnesia  and  lime,  which  the  turquoise  does  not. 
Lapis  lazuli,  which  is  also  occasionally  mistaken  for 
turquoise,  belongs  to  the  regular  or  isometric  system ; 
it  is  commonly  massive  or  compact,  and  is  a  silicate  of 
alumina  with  some  lime  and  iron.  It  is  found  in  sye- 
nite, crystalline,  limestone,  and  often  associated  with 
pyrites  and  mica. 

Topaz  belongs  to  the  orthorhombic  system.  It  is  a 
silicate  of  alumina  with  fluorine.  Powdered,  mixed, 
and  heated  with  microcosniic  salt  in  the  open  tube, 
fluorine  is  disengaged  with  its  characteristic  odor,  and 
etching  action  upon  glass.  With  the  blow  pipe  on 
charcoal,  heated  with  the  cobalt  solution,  it  gives  the 
fine  blue  color  of  alumina. 

The  explorer  who  comes  upon  any  hard,  brightly 
colored  stone,  that  may  possibly  turn  out  a  gem, 
should  preserve  it  carefully  until  he  returns  to  some 
city,  when  it  should  be  submitted  to  an  expert.  The 
value  of  a  gem  depends  upon  so  many  qualities  that 


86  ABC  OF  MINING. 

it  were  hopeless  for  the  tyro  to  endeavor  to  arrive  at 
any  just  estimate  of  it.  He  might  ruin  a  superb  speci- 
men, without  becoming  one  bit  the  wiser.  A  few  of 
the  more  prominent  characters  of  valuable  gems  fol- 
low: 

Name,         Sp.  Gravity.  Hardness.  Color. 

Aquamarine  2.7  7.7  Blue. 

Emerald  2.7  7.5  Green. 

Diamond  3.5  10.0  Colorless. 

Garnet  4.1  7.0  Claret. 

Opal  2.2  6.0  Opaline. 

Ruby  3.5  8.0  Dark  red. 

Tourmaline  3.1  7.3  Various. 

Turquoise  2.7  6.0  Blue,  green. 

Untramarine  2.5  5.8  Blue  to  green. 

Graphite.  This  mineral  is  commonly  known  as 
black  lead,  or  plumbago.  It  is  the  same  in  composi- 
tion as  the  diamond,  viz.:  loo  per  cent  carbon.  Spe- 
cific gravity,  2  to  2.2.  Hardness,  1.2  to  1.9.  Color, 
black.  Greasy.  Of  value  when  free  from  impurities. 
Used  in  making  pencils,  stove  polish,  crucibles,  etc. 
Found  in  the  earlier  rocks. 

Gypsum.  A  sulphate  of  lime  occurring  in  great 
beds.  Burnt,  it  becomes  plaster  of  paris. 

Iron.  This,  the  most  important  of  all  metals,  is 
found  in  various  forms.  The  ores  of  iron  are: 

Sp.  Gravity.  Hardness.  P  C.  Fe. 

Native  ore  7.7  4.5  100 

Magnetite  5.1  6.0  72 

Hematite  4.8  6.0  70 

Limonite  3.8  5.2  60 

Siderite  3.8  4.0  62 

Pyrite  5.0  6.3  47 


ECONOMIC  ORES  AND  MINERALS.  87 

Native  iron  is  only  found  in  meteorites  that  have 
come  from  space. 

Magnetite  is  loadstone  ore;  the  powder  is  reddish 
black,  and  the  ore,  dark  brown  to  black.  It  is  found 
in  the  older  rocks  and  is  an  important  ore. 

Hematite  varies  from  metallic  to  dull  in  luster. 
There  are  many  varieties  of  it,  known  as  ironstone, 
ocher,  needle  ore,  etc.  Hematite  may  be  slightly  mag- 
netic. Immense  beds  exist  in  the  triassic  sandstones, 
and  in  the  secondary  rocks  below  the  coal  measures. 
The  powder  and  streak  of  limonite  are  always  yellow; 
it  is  an  important  ore.  Siderite  assumes  many  forms. 
It  is  called  spathic  ore,  clay-ironstone,  carbonate  of 
iron,  black  band,  etc.  Most  of  these  carbonate  iron 
ores  only  range  between  30  and  40  per  cent  of  metal- 
lic iron,  but  are  in  demand  as  fluxes  for  other  iron  ores. 
,The  pyritic  ores  of  iron,  including  marcasite,  pyrrho- 
tite  and  mispickel,  are  often  taken  for  gold  by  the  in- 
experienced. In  an  accessible  region  pyrites  may  be 
valuable,  as  they  are  bought  by  makers  of  sulphuric 
acid. 

Iron  is  so  low  in  price  that  vast  deposits  exist  which 
cannot  be  made  use  of  because  they  would  be  too  ex- 
pensive to  mine.  A  deep  bed,  or  a  narrow  one,  or 
the  slightest  difficulty  in  transportation,  would  pre- 
clude any  profitable  development.  It  is  known  that 
enormous  areas  in  northern  Labrador,  for  instance, 
are  full  of  iron  deposits,  yet  there  seems  no  chance  of 
their  having  the  slightest  economic  value  for  a  long 
time,  if  ever.  Conditions  of  commerce  very  different 


88  ABC    OF    MINING. 

to  those  now  obtaining  will  have  to  exist  before  they 
can  be  utilized. 

Iron  ore  is  most  favorably  situated  for  profitable  ex- 
traction when  it  is  near  coking  coal  and  beds  of  lime- 
stone; the  former  for  fuel,  the  latter  for  flux.  Occa- 
sionally such  regions  as  that  of  Lake  Superior  may  be 
able  to  compete  successfully  with  others,  although 
they  do  not  possess  the  necessary  smelting  facilities, 
because  these  deficiencies  are  counterbalanced  by  in- 
exhaustive  stores  of  easily  mined  ores,  and  transpor- 
tation facilities  unrivaled  in  cheapness. 

Lead.  The  two  important  sources  of  supply  are 
galena  and  cerussite.  The  former  contains  87  per 
cent  of  lead,  and  frequently  some  silver  and  gold.  It 
is  so  distinctive  as  to  be  easily  recognized.  Luster, 
metallic;  opaque;  lead-gray;  harsh.  Brittle  to  sectile 
(may  be  cut).  Cleavage,  perfect.  Fracture,  even  to 
sub-conchoidal.  Structure,  granular  or  foliated,  tab- 
ular, or  fibrous.  Specific  gravity  is  7.5,  and  hardness, 
2.6. 

The  carbonate  cerussite  contains  about  79  per  cent 
lead.  Luster,  vitreous  to  resinous.  Translucent. 
Color,  gray.  Smooth.  Brittle.  Cleavage,  perfect  to 
imperfect.  Fracture,  conchoidal.  Massive  to  granu- 
lar. Rich  carbonate  ores  look  like  clay,  and  are  un- 
doubtedly often  passed  by. 

The  economic  ores  of  lead  are: 

Lead. 

Galena  PbS  86.6  p.  c. 

Cerusite  PbCO8  77.5  p.  c. 

Anglesite  PbSO4  67.7  p.  c. 

Pyromorphite        Pb3P2O8  plus  1-3  PbCl2       75.36  p.c. 


ECONOMIC  ORES  AND  MINERALS.  89 

Lead  ores  are  frequently  rich  in  silver.  They  occur 
in  limestone,  sandstone,  granite  and  clay.  The  com- 
mercial ores  are  galena,  which  is  easily  recognized  by 
its  steel-like  cubes,  and  the  carbonates.  These  latter 
are  like  lightly  colored  clays  when  in  powder  and  are 
very  apt  to  be  overlooked.  Fluor  spar  is  as  favorable 
a  gangue  for  lead  as  quartz  is  for  gold. 

The  Rocky  Mountains  are  the  principal  American 
sources  of  this  metal,  but  a  very  large  amount  comes 
from  the  Mississippi  valley.  In  the  mountains  the 
ore  is  a  by-product,  in  silver  smelting,  being  obtained 
from  argentiferous  galena,  while  in  Missouri,  Kansas, 
Wisconsin  and  Illinois  lead  and  zinc  are  found  free 
from  any  mixture  with  the  precious  metal.  The  age 
of  these  deposits  varies  from  lower  Silurian  or  cam- 
brian  to  the  carboniferous. 

The  ore  is  found  in  limestone  rocks, — sometimes  in 
flat  openings  parallel  to  the  almost  horizontal  beds,  or 
else  in  gash  veins  almost  at  right  angles  to  these.  As 
lead  is  often  found  in  dolomite  limestone,  that  is,  lime- 
stone carrying  almost  as  much  magnesia  as  lime,  and 
this  rock  was  undoubtedly  deposited  in  a  shallow  sea, 
geologists  incline  to  the  belief  that  therefore  the  lead 
is  due  to  a  growth  of  seaweeds  in  whose  ash  this  metal 
and  zinc  are  known  to  occur.  At  any  rate,  these  de- 
posits now  have  great  economic  value,  and  tHe  lead 
and  zinc  ore  is  easily  got  at. 

Galena  and  zinc  blende  frequently  resemble  one  an- 
other, but  they  may  be  distinguished  by  this  infallible 
sign:  the  powder  of  galena  is  black,  and  that  of  blende 
brown,  or  yellow. 


90  ABC   OF    MINING. 

Lithographic  Stone.  This  is  a  very  fine  grained 
compact  limestone  from  Bavaria.  So  far  nothing 
equal  to  the  imported  stone  has  been  found  in  Amer- 
ica. The  distinguishing  qualities  are:  Gray,  drab  or 
yellow;  porous,  yet  not  too  soft;  of  fine  texture,  and 
free  from  veins  and  inequalities. 

Manganese.  Manganese  ores  in  1899  amounted  in 
the  United  States  to  143,256  tons,  value  $306,476. 
This  mineral  is  used  for  bleaching  and  making 
oxygen,  and  in  steel  manufacture.  Pyrolusite 
contains  63  per  cent  manganese.  Hardness,  2.3. 
Specific  gravity,  4.8.  Luster,  metallic.  Opaque.  Gray 
to  bluish  black.  Harsh.  Brittle.  Cleavage,  imper- 
fect. Fracture,  uneven.  Granular,  massive.  Manga- 
nite  is  harder,  4.0;  its  specific  gravity  is  4.3.  Luster, 
sub-metallic.  Cleavage,  perfect.  Texture,  fibrous. 
Wad  is  an  impure  ore  of  manganese  found  in  bogs,  of 
little  or  no  value. 

Pyrolusite  MnO2  63.2 

Braunite  Mn2O3  69.68 

Psilomelane  (Variable)  ? 

Franklinite,  a  zinc-manganese  ore,  is  also  a  com- 
mon source  of  supply.  An  ore  to  be  commercially 
valuable  should  contain  from  40  to  60  per  cent  metallic 
manganese,  and  not  over  0.2  to  0.25  per  cent  phos- 
phorus. 

To  determine  the  value  of  manganese  ores  a  some- 
what intricate  calculation  is  necessary.  Delivered  at 
Bessemer,  Pa.,  the  Carnegie  Steel  Company  pays  ac- 
cording to  the  following  sliding  scale: 


ECONOMIC  ORES  AND  MINERALS.  91 

Per  cent  Mn.  Per  Unit 

over  49  p.  c.  Fe.  Mn. 

46  49  p.  c.  6c  28c 

43  46  p.  c.  6c  2;c 

40  43  p.  c.  6c  26c 

37  40  p.  c.  6c  250 

34  37P-c.  6c  240 

31  34  P- c.  6c  230 

6c      22C 

Moreover,  for  each  one  per  cent  of  silica  in  excess 
of  eight  per  cent  a  deduction  of  fifteen  cents  a  ton  is 
made,  and  a  deduction  of  one  cent  per  unit  of  manga- 
nese is  made  for  each  2-100  of  one  per  cent  of  phos- 
phorous present  in  excess  of  l-io  per  cent.  From 
which  it  is  evident  that  there  can  be  little  profit  in 
impure  deposits  of  manganese. 

Mercury.  Quicksilver  usually  occurs  in  the  form 
of  cinnabar,  though  occasional  deposits  of  pure  metal 
are  found  in  drops  and  small  pockets,  in  limestone  and 
the  softer  secondary  rocks,  including  shales  and  slates. 
As  the  appearance  of  quicksilver  must  be  familiar  to 
all,  cinnabar  alone  needs  description.  Its  specific 
gravity  is  9.0;  its  hardness,  2.2.  It  is  a  red  brown 
earthy  ore,  the  powder  of  which  is  a  dull  red.  It  is 
generally  found  in  sandstone,  though  it  occasionally 
occurs  in  slates,  shales  and  serpentine.  Heated  gently 
with  lime  cinnabar  yields  quicksilver.  If  copper  be 
held  over  the  fumes  of  mercury  it  will  be  coated  with 
a  light  film  of  the  metal.  An  alloy  with  silver  has  been 
found.  Mercury  is  heavy,  extremely  brilliant,  and 
mobile.  The  composition  of  cinnabar  is: 


92 


ABC   OF   MINING. 


Cinnabar  HgS 


Per  cent  Hg. 
86.2 


Although  but  three  American  states  have  supplied 
this  metal,  this  country  has  held  rank  as  second  pro- 
ducer. Of  these  California  is  by  far  the  most  impor- 
tant. Oregon  and  Utah  having  never  had  any  but  a 
small  and  spasmodic  output.  Judging  by  Californian 
experience,  the  prospector  is  most  likely  to  find  cinna- 
bar, the  ore  from  which  the  quicksilver  of  commerce 
is  derived,  in  metamorphic  rocks.  Mercury  is  always 
sold  in  flasks  of  76^  pounds.  The  production  of  mer- 
cury by  the  United  States  (California)  was  28,879 
flasks  in  1899,  which  were  valued  at  $1,155,160. 

The  following  table  shows  the  rock  in  which  the 
most  famous  Californian  quicksilver  mines  are: 


Mine. 

Sulphur  Creek 
Abbott 

Great  Western 
JEtna. 
Corona 
Aat  Hill 
New  Almaden 
Barton 

Cinnabar  King 
Altoona 


County. 
Col  usa 

Lake 

Lake 

Napa 

Napa 
Napa 

Santa  Clara 
Siskiyou 

Sonoma 
Trinity 


Rock. 
Serpentine. 
Shale-serpentine. 
Serpentine.  (?) 
Sandstone. 

Sandstone-serpentine. 
Sandstone. 
Shale-serpentine. 
Shale-sandstone. 
Sandstone-serpentine. 
Porphyry-serpentine. 


A  study  of  the  foregoing  shows  that  serpentine  is 
almost  as  intimately  connected  with  quicksilver  as  is 
quartz  with  gold,  or  granite  with  tin.  These  are  the 
things  that  prospectors  should  make  a  note  of.  With 
the  great  increase  of  gold  mining  and  the  limited  store 


ECONOMIC  ORES  AND  MINERALS.  93 

of  cinnabar  that  is  available  that  ore  seems  certain  to 
rise  in  value  before  long. 

Mica.  The  value  of  Indian  mica  varies  from  QOC 
a  pound  for  sheets  4  in.  x  I  in.  to  $13  a  pound  forsheets 
10  in.  x  8  in.  The  white  mica  in  large  sheets  is  valu- 
able. The  amber-colored,  and  spotted,  are  used  for 
insulating  purposes  in  electric  plants,  while  the  coarser 
sorts  are  ground  and  used  as  lubricants,  or  in  fire-proof 
paint  manufacture. 

Nickel.  This  ore  is  never  found  in  metallic  form, 
but  always  in  combination.  Pyrrhotite,  or  magnetic 
pyrites,  is  the  source  of  about  all  the  nickel  of  com- 
merce. This  ore  has  been  already  noticed  under  iron. 
Rare  but  valuable  ores  of  nickel  are  millerite,  nickel- 
ite,  glance,  and  nickel  bloom. 

Per  cent  nickel. 

Millerite  NiS  64.4 

Niccolite  NiAs  44.0 

Some  of  the  nickel  of  commerce  is  derived  from 
nickelliferous  pyrrhotite. 

Petroleum.  Crude  petroleum  is  never  found  in 
metamorphic  or  igneous  rocks.  The  stratified  rocks 
of  the  Devonian,  Carboniferous  and  Cretaceous  ages 
are  most  likely  to  hold  it.  The  crude  oil  is  almost 
black,  and  consists  of  about  85  per  cent  of  carbon, 
and  15  per  cent  of  hydrogen.  A  long  iron-shod  stick 
is  all  the  prospector  requires  to  take  with  him  in  his 
search  for  surface  indications  of  oil.  The  warmer  the 
day  the  easier  the  search,  as  the  oil  rises  to  the  surface 
of  the  streams,  and  is  found  in  greater  quantities  than 
on  cold  days. 


94  ABC   OF   MINING. 

Oil  existing  in  the  lower  rocks  ascends  through 
them  unti|  it  accumulates  under  some  layer  that  will 
not  let  it  pass  through.  In  this  condition  deep  boring 
finds  it,  the  rod  usually  tapping  gas  first.  Petroleum 
may  be  noticed  oozing  out  of  gravel  banks,  or  float- 
ing as  a  scum  on  the  surface,  whenever  abundant.  It 
has  been  found  in  rocks  of  widely  different  age,  from 
extremely  ancient  formations  to  some  that  did  not 
precede  man  by  so  very  long,  geologically  speaking. 

Platinum.  This  metal  is  only  found  native.  Its 
gravity  is  very  high,  from  16  to  22.  Hardness,  4  to 
4.5.  Luster,  metallic.  Opaque.  Whitish-gray. 
Smooth.  Ductile.  Cleavage,  none.  Fracture,  hack- 
ly. Texture,  granular,  fine.  Platinum  is  unaffected 
by  acids,  but  if  alloyed  with  10  per  cent  of  silver  it  dis- 
solves in  nitric  acid.  Almost  infusible.  Platinum  oc- 
curs with  placer  gold  in  the  beds  of  streams.  Usually 
it  is  in  small  grains,  but  one  or  two  large  nuggets  are 
on  record  from  Brazil  and  Siberia.  Serpentine  rocks 
are  believed  to  have  originally  held  the  platinum  found 
in  the  beds  of  rivers,  but  none  has  been  found  in  veins. 
The '  entire  product  of  the  United  States  was  300 
ounces -in  1898;  valued  at  $3,837.  In  1899  there  was 
none  produced. 

Silver.  Silver  is  generally  found  in  serpentine,  trap, 
sandstone,  limestone,  shale,  or  porphyry  rocks,  the 
gangue  being  quartz,  calc,  fluor,  or  heavy  spar.  All 
silver  ores  are  heavy,  and  many  of  them  are  sectile, 
i.  e.,  may  be  cut  with  the  knife.  Western  men  test  for 
silver  by  heating  the  ore  and  dipping  it  into  water. 


ECONOMIC  ORES  AND  MINERALS.          95 

Some  metal  comes  to  the  surface  in  a  greasy  scum, 
should  silver  be  present.  Native  silver  is  found  occa- 
sionally. Owing  to  the  fall  in  value  of  this  metal  its 
future  is  not  assured.  It  has  fallen,  during  the  past 
year,  once  to  forty-nine  cents  an  ounce,  and  this  has 
had  a  most  disastrous  effect  upon  many  silver  mines, 
forcing  them  to  suspend  operations.  Should  the  fall 
continue,  as  seems  likely,  and  the  price  of  silver  go 
down  to  forty  cents  an  ounce,  little  will  be  produced 
except  as  a  by-product  in  the  treatment  of  argentifer- 
ous lead  ores. 

As  silver  enters  into  chemical  combination  with  sul- 
phur easily,  as  is  seen  by  the  black  film  that  forms  on 
silver  articles  in  a  room  wihere  gas  is  burnt,  most  sil- 
ver ores  are  sulphides.  The  very  abundance  of  silver 
has  caused  its  great  fall  in  value,  and  it  does  not  ap- 
pear that  it  is  ever  likely  to  remain  for  long  at  a  price 
exceeding  fifty  cents  an  ounce,  owing  to  the  ease  with 
which  it  may  be  produced,  and  the  large  quantities 
that  must  find  their  way  to  market  through  it  being  a 
by-product  in  lead  smelting.  From  1859  to  1891  the 
Comstock  lode  in  Nevada  produced  $325,000,000. 
This  lode  is  a  belt  of  quartz,  10,000  feet  long  and  sev- 
eral hundred  wide,  and  is  a  contact  vein  between  dio- 
rite  and  diabase.  In  America  galena  is  the  principal 
source  of  silver;  the  chlorides  and  oxides  rank  next; 
while,  lastly,  some  silver  is  parted  from  gold  when  it 
reaches  the  mint,  as  gold  always  contains  more  or  less 
of  that  metal.  No  precise  statement  as  to  the  manner 
of  its  occurrence  may  be  made  since  it  is  found  in  many 
different  positions,  and  is  associated  with  all  sorts  of 


96  ABC   OF    MINING. 

minerals.  It  is  never  found  in  placer  deposits,  as  it 
breaks  up  under  the  influence  of  water,  air,  etc.  Its 
original  source  is  doubtless  the  igneous  rocks,  where 
it  occurs  in  association  with  augite,  hornblende  and 
mica.  Silver  may  be  expected  in  mountainous  regions 
of  recent  origin.  Between  1875  and  1891  the  world's 
product  rose  from  $82,000,000  to  $185,599,600.  Three 
quarters  of  this  came  from  the  western  hemisphere. 
The  commercial  ores  of  silver  are: 

Silver. 

Argentite  Ag2S  87.1  per  cent 

Proustite  3Ag2SAs2S3       65.5  per  cent 

Prysagyrite  3Ag2SSb2S3         59.9  per  cent 

Stephanite  5Ag2SSb2S3         68.5  per  cent 

Cesargerite  AgCl  75.3  per  cent 

The  Anaconda  mine  in  Butte  is  the  largest  producer 
of  silver  in  the  country.  In  1896  its  output  was  5,000,- 
ooo  ounces.  The  Anaconda  is  also  the  heaviest  cop- 
per producer  in  the  United  States,  its  yield  of  copper 
being  125,350,693  pounds. 

Sulphur.  Brimstone  is  found  native  in  the  neigh- 
borhood of  volcanoes,  extinct  or  active.  It  is  also  de- 
rived from  iron  pyrites.  Color,  yellow.  Hardness,  2. 
Specific  gravity,  2.  Luster,  resinous.  Smooth.  Sec- 
tile.  Texture,  crystalline. 

Talc.  The  scientific  name  of  this  mineral  is  stea- 
tite. It  contains  silica  and  magnesia.  Its  green  color, 
pearly  luster,  and  greasy  feel,  are  very  characteristic. 
It  is  not  attacked  by  boiling  sulphuric  acid.  Useful  in 
the  arts,  but  of  no  great  value. 

Tin.     The  composition  of  casseterite,  the  commer- 


ECONOMIC  ORES  AND  MINERALS.       97 

cial  ore  of  tin,  is  SnO2 ;  equal  to  78.67  per  cent  of  me- 
tallic tin.  Cassiterite  or  tin  stone  is  a  heavy  ore  which 
occurs  in  alluvial  deposits  or  in  the  beds  of  streams. 
It  will  be  one  of  the  latest  ores  the  young  prospector 
will  find  himself  able  to  name  with  certainty.  Granite, 
with  white  mica  as  one  of  its  constituents,  has  so  far  al- 
ways been  associated  with  tin.  The  American  conti- 
nent yields  little  tin,  and  it  is  not  likely  the  prospector 
in  either  the  western  states  or  in  Canada  will  stumble 
upon  it,  though  a  good  deposit  of  stream  tin  would  en- 
rich him  in  a  short  time,  for  the  metal  is  in  great  de- 
mand. The  streak,  when  the  metal  is  scratched  with 
a  knife  point,  is  whitey-gray  and  very  distinctive. 

Tin  may  some  day  be  found  in  the  northern  Rockies, 
as  there  is  plenty  of  granite,  which  is  favorable  to  this 
metal.  It  is  worth  about  thirteen  cents  a  pound,  and 
a  vein  must  yield  more  than  five  per  cent  of  metal  to 
pay  the  cost  of  mining  and  dressing.  Cassiterite,  the 
principal  tin  ore,  would  have  to  be  roasted.  Most  of 
the  European  tin  mines  were  first  worked  for  the  cop- 
per they  contained.  The  copper  was  found  in  the  cap- 
ping, but  as  they  gained  in  depth  they  became  more 
and  more  valuable  for  their  tin.  Some  of  the  Corn- 
ish mines  are  three-quarters  of  a  mile  in  depth.  Very 
lately  tin  has  been  discovered  and  mined  in  vast  quan- 
tities in  the  Straits  Settlements,  India.  As  it  is  found 
in  the  streams  the  expense  of  mining  is  very  light,  and 
it  is  killing  the  European  mines.  The  Cornish  miners 
put  their  tin  ore  on  a  shovel  when  they  wish  to  test  it. 
The  sample  is  first  crushed  fine  and  a  few  skillful  shakes 
get  rid  of  all  the  gangue,  leaving  behind  the  tin  and 


98  ABC   OF   MINING. 

wolfram.  This  wolfram  is  always  associated,  in  Corn- 
wall, with  the  tin  and  it  is  got  rid  of  by  roasting.  Aus- 
tralasia and  Cornwall  produce  most  of  the  tin  used  in 
commerce.  Tin  is  not  found  native.  Specific  gravity 
of  cassiterite  is  6.5  to  7.  Hardness,  6.5  to  7.  Luster, 
vitreous  to  adamantine.  Translucent  to  opaque. 
Brown,  black,  gray,  red  or  yellow.  Har.sh.  Brittle. 
Massive.  The  appearance  of  this  metal  is  so  variable 
that  nothing  but  a  test  with  reagents  determines  it 
with  certainty.  Granite  is  freqently  the  country  rock 
in  which  tin  is  found. 

Zinc.  This  is  another  ore  that  never  occurs  native. 
Calamine  or  silicate  of  zinc  is  the  great  producing  ore. 
Composition:  Zinc  oxide,  67  per  cent;  silicate,  25  per 
cent;  water,  8  per  cent.  Specific  gravity,  3  to  3.7. 
Hardness,  4.6  to  5.  Luster,  vitreous.  Translucent. 
White.  Harsh.  Brittle.  Cleavage,  perfect.  Fracture, 
uneven.  Texture,  granular  crystalline.  Calamine  is  a 
difficult  mineral  to  detect  without  experience,  as  when 
impure  it  does  not  look  in  the  least  like  a  metallic  ore. 
It  would  be  taken  for  clay  or  shale.  This  ore  results 
from  the  decomposition  of  zinc  blende.  Blende  con- 
tains 67  per  cent  zinc  and  33  per  cent  sulphur.  It  is 
often  dark  brown  or  black  from  iron,  otherwise  it  may 
be  red,  green  or  bluish.  It  is  a  troublesome  impurity 
in  silver  ores.  Smithsonite  is  a  carbonate  much  re- 
sembling, and  often  found  with,  calamine.  Other  zinc 
ores  are  merely  curiosities  and  do  not  affect  the  com- 
mercial value  of  the  metal. 

In  the  New  Jersey  mines  the  zinc  ores  are  the  ox- 
ides zincite  and  willemite,  and  the  zinc-iron  oxide 


ECONOMIC  ORES  AND  MINERALS.          99 

franklinite.  In  the  Missouri  region,  on  the  other 
hand,  sphalerite  and  blende  are  the  typical  ores. 
Blende  generally  associates  with  the  lead  sulphide,  ga- 
lena. The  Joplin  district  in  southwestern  Missouri 
and  the  adjoining  region  in  Kansas  are  now  mainly 
supplying  the  markets  of  the  country,  though  the  New 
Jersey  deposits  are  very  valuable. 

Joplin  ore  assaying  58  to  62  per  cent  has  varied 
greatly  in  price  during  the  past  four  years.  The 
lowest  quotation  was  $20  a  ton,  the  highest  $51.50. 

Zinc  is  derived  mainly  from  the  following  half 
dozen  ores : 

Zinc. 

Sphalerite  ZnS.  67.0  per  cent. 

Zincite  .       ZnO  80.3  per  cent. 

Smithsonite  ZnOCCX  51.9  per  cent. 

Franklinite  (Variable)  (?)  5.54  per  cent. 

Willemite  2ZnO.SO2  58.5  per  cent. 

Calamine  2ZnO.SiO2.HO2      54.2  per  cent. 


100  ABC   OF    MINING. 


CHAPTER  V. 
MINING. 

Although  the  scope  of  this  work  does  not  include  the 
very  complex  problem  involved  in  the  working  of  a 
great  mine,  prospecting  and  the  simpler  mining  opera- 
tions are  so  intimately  connected  that  it  would  not  be 
desirable  to  make  mention  of  the  one  and  ignore  the 
other,  because  the  prospector  must  perforce  become  a 
miner  as  soon  as  he  discovers  mineral,  even  though  his 
operations  should  not  go  beyond  a  shallow  trial  shaft. 

The  simplest  method  of  hoisting  dirt  or  rock  out  of 
a  shaft,  after  it  has  become  too  deep  for  the  sinker  to 
throw  the  stuff  out  with  a  spade,  is  by  a  bucket  and 
windlass,  which  may  be  either  single  or  double,  ac- 
cording to  the  power  required.  In  northwestern  Can- 
ada, where  the  present  gold  excitement  has  attracted 
so  many  thousand  pioneers,  the  miners  have  hitherto 
been  content  with  a  windlass.  For  their  purpose  it 
answers  well,  as  they  sink  through  gravel  and  not  more 
than  thirty  Jeet  at  the  most  before  reaching  the  bed 
rock.  The  alluvial  flats  in  which  the  coarse  gold  of 
the  upper  Yukon  has  been  discovered,  are  composed  of 
gravel  that  is  invariably  frozen,  summer  as  well  as  win- 
ter, and  which  requires  to  be  thawed  out  before  it  can 
be  worked  with  a  pick.  Strangely  enough,  dynamite 
cannot  be  used,  as  the  ground  is  so  elastic  under  the 
frost  that  the  tamping  simply  blows  out  and  the  re- 


MINING.  101 

quired  effect  is  not  produced.  This  peculiar  condi- 
tion has  led  the  men,  who  are  mining  in  that  part  of 
the  continent,  to  adopt  methods  very  similar  to  those 
used  in  Siberia,  where,  also,  the  ground  is  permanently 
frozen  to  a  great  depth.  After  scratching  the  surface 
of  the  soil,  and  removing  the  deep  moss  that  invariably 
covers  it,  they  light  large  fires  over  night  and  in  the 
morning  remove  the  few  inches  of  thawed  soil  under- 
neath the  ashes.  By  this  painfully  slow  method  they 
eventually  sink  to  the  richer  gravel,  fifteen  or  twenty, 
or  even  thirty,  feet  below  the  surface,  though  there  are 
few  shafts  of  this  depth  on  the  Klondike  and  the  other 
gold-bearing  creeks  about  which  we  have  heard  so 
much.  When  the  bed  rock  is  reached  and  the  few 
inches  of  decayed  surface  removed,  the  miner  builds 
his  fire  against  the  side  of  the  shaft,  placing  some  in- 
clined logs  over  it  as  a  roof,  and  goes  to  bed.  When 
he  awakes  next  day  several  feet  of  the  soil  have  fallen 
down  over  the  logs,  and  this  he  has  to  hoist.  It  is 
at  this  stage  that  the  windlass  worked  by  his  compan- 
ion, or  partner,  demonstrates  its  value.  In  a  very  short 
time  all  the  gravel  that  the  fire  has  thawed  out  is  hoisted 
to  the  surface,  and  added  to  the  dump,  where  it  must 
remain  until  the  warmth  of  summer  shall  'have 
thawed  the  streams  and  permitted  sluicing. 

A  sluice  is  really  nothing  more  nor  less  than  a 
trough,  open  at  the  top,  in  which  the  gold  is  sorted 
from  the  lighter  gravel  and  dirt  by  running  water.  The 
grade  varies  according  to  the  coarseness  of  the  gold. 
Very  fine  gold  would  be  carried  away  by  too  swift  a 
current,  while  coarse  gold  will  resist  almost  a  torrent. 


102 


ABC    OF    MINING. 


The  sluice  is  built  in  joints,  usually  a  dozen  feet  in 
length ;  the  sides  may  be  six  inches  or  a  foot  deep,  and 
the  width  varies  from  one  to  two  feet.  There  is  no 
rule  in  this  matter,  but  owing  to  the  extravagant  price 
of  lumber — as  much  as  a  hundred  and  fifty  dollars  a 
thousand  feet,  board  measure — the  tendency  is  to 
make  the  sluices  very  small  and  very  short,  thereby 
saving  nothing  but  the  very  coarsest  gold.  A  prop- 


MINER'S  GOLD  PAN. 

erly  constructed  sluice  should  be  several  hundred  feet 
in  length,  and  the  inclination  should  not  be  more  than 
one  foot  in  twelve,  while  it  may,  in  a  case  of  fine  gold, 
be  advisable  to  diminish  this  inclination  by  at  least  a 
fourth.  Riffles,  or  cross-pieces,  are  placed  across  the 


MINING.  103 

sluice  at  intervals  of  a  few  feet,  and  slats  are  placed 
lengthwise,  filling  up  the  intervals  between  the  riffles. 
Into  the  crevices  and  interstices  of  these  obstructions 
the  heavy  gold  sinks  by  its  own  weight,  and  every  few 
days,  or  weeks,  as  the  case  may  warrant,  the  miner 
shuts  off  the  water  by  closing  the  gate  at  the  head  of 
the  sluice,  removes  the  slats  and  riffles,  beginning  at 
the  joint  nearest  the  head  and  working  towards  the  tail 
of  the  sluiceway,  and  collects  all  the  gold  that  has  ac- 
cumulated. 

This  is  a  very  simple  form  of  mining,  but  it  is  not 
the  simplest.  Much  gold  has  been  recovered  from  the 
gravel  in  which  nature  has  placed  it  by  the  aid  of  the 
pan,  a  sheet  iron  dish  modeled  on  the  housewife's 
bread  pan. 

Next  to  the  pan  the  cradle  is  as  little  complicated  as 
anything  used  in  the  winning  of  gold. 

After  this  comes  the  long  torn,  a  considerable  im- 
provement upon  the  cradle,  but  it  necessitates  more 
water  and  more  men. 

The  horse  whim  is  used  in  developing  many  a  west- 
ern prospect.  The  windlass  does  not  work  well  below 
forty  feet,  and  where  fuel  and  water  are  to  be  had  any 
sensible  man  will  use  steam  power  for  deep  mining, 
but  there  is  a  gap  between  the  windlass  and  the  steam 
hoist  which  the  horse  whim  fills  acceptably.  To  a 
depth  of  300  feet  a  horse  whim  can  usually  handle  the 
rock  and  water.  It  is  inexpensive,  in  the  first  outlay, 
and  costs  but  little  to  run.  You  can  bring  your  bucket 
from  a  shaft  a  hundred  and  fifty  feet  deep  in  two  and 
a  half  minutes,  and  with  a  seven  hundred  pound  capac- 


104 


ABC   OF   MINING. 


MINING.  105 

ity  in  the  bucket,  in  forty-five  trips  you  could  raise 
fifteen  tons  a  day.  A  shaft  three  hundred  feet  deep 
would  require  four  hours'  steady  work  to  bring  to  sur- 
face the  same  amount.  A  fair  speed  with  a  one-horse 
whim  from  a  three  hundred  foot  shaft  is  one  hundred 
buckets  per  shift  of  ten  hours,  but  the  prospector  rarely 
has  to  figure  on  shafts  of  that  depth.  If  the  mine  turns 
out  well  it  is  likely  to  be  in  the  'hands  of  a  powerful 
company  (of  which  he  should  be  the  principal  share- 
holder) before  the  three  hundred  foot  level  is  reached. 
The  weight  of  the  horse  whim  is  about  eight  hundred 
pounds.  It  can  be  taken  to  pieces  and  packed  any- 
where that  a  mule  can  travel;  the  heaviest  piece  will  not 
weigh  more  than  a  hundred  pounds. 

A  small  stamp  mill,  run  by  ihorse  power,  is  a  very 
favorite  machine  with  western  men,  where  the  ore  is 
free  milling.  The  mortar  in  which  the  stamps  work 
has  copper  plates  amalgamated  with  mercury  inside, 
and  copper  tables  with  amalgamated  plates  over  which 
the  pulp  passes  after  oozing  through  a  fine  screen  in 
front  of  the  mortar.  These  little  mills  are  so  con- 
structed that  they  can  be  taken  apart  or  put  together 
in  an  hour  or  two.  They  require  but  one  horse  power 
and  will  do  good  clean  work  up  to  their  capacity.  The 
following  are  the  specifications  of  a  good  one: 

Total  weigfit 1,500  pounds. 

Weight  of  heaviest  piece. 350  pounds. 

Weight  of  stamp 100  pounds. 

Drops  per  minute 60  to  80. 

Capacity  per  hour 300  to  400  pounds. 

Diameter  of  pulley 30  inches. 

Price,  with  horse  power, about  $350. 


io6 


ABC   OF    MINING. 


MINING.  107 

A  diamond  drill  is  a  most  useful  adjunct  to  explora- 
tion of  a  mine  or  deposit.  It  is,  essentially,  a  hollow 
drill  which  may  be  lengthened  at  will,  rotating  rapidly 
and  carrying  a  crown  of  "bort"  or  black  diamonds  at 
its  extremity,  that  eats  into  the  strata  very  quickly. 
Holes  3,000  feet  deep  have  been  driven  by  the  diamond 
drill,  but  such  extensive  investigations  of  the  earth's 
crust  are  tremendously  costly,  and  may  only  be  un- 
dertaken by  governments  or  rich  companies.  For  a 
depth  of  700  feet,  however,  the  expense  need  not  ex- 
ceed $2,100.  The  cost  of  the  plant  for  drilling  would 
be  $3,500  more.  Water  is  pumped  down  the  hollow 
center  of  the  drill,  to  keep  it  cool.  The  great  advant- 
age of  the  diamond  over  the  percussion  drill  is  that  it 
permits  the  saving  of  a  core,  so  that  the  character  of 
the  rocks  and  minerals  passed  through  may  be  known. 
The  diamond  drill  does  better  work  in  hard  strata  than 
it  does  in  soft.  The  rate,  in  limestone,  may  be  about 
two  feet  an  hour,  down  to  a  depth  of  200  feet. 

A  complete  outfit  for  boring  with  the  diamond  drill 
includes  a  steam  engine  and  boiler,  diamond  crown, 
lining  tubes,  rods,  and  various  minor  accessories. 

Hydraulic  mining  is  the  cheapest  known  method  of 
recovering  gold.  In  four  years  the  North  Bloomfield 
Mining  Company  of  California  worked  325,000,000 
cubic  yards,  which  yielded  only  2.9  cents  of  gold  per 
cubic  yard,  and  realized  some  profit.  Very  poor 
gravel  will  pay  when  the  conditions  are  good.  Cheap 
water,  grades  of  four  inches  in  a  hundred,  ample  dump- 
ing room,  big  banks  of  light  gravel,  large  areas  of  de- 
posits, labor  at  a  dollar  a  day,  and  a  clever  superin- 


108  ABC   OF    MINING. 

tendent,  make  a  combination  that  will  yield  a  profit  out 
of  three-cent  gravel. 

Miners  speak  of  "surface"  and  "deep"  placers;  of 
"hill  claims;"  of  "bench  claims"  on  the  old  river  ter- 
races; of  "gulch  diggings;"  of  "bar  claims"  on-  the 
sand  bars  of  existing  rivers;  of  "beach  sands"  or  those 
that  in  a  few  favored  localities  border  the  ocean.  A 
"sluice"  is  a  long  boxway  to  catch  the  gold;  a  ''drift" 
is  a  tunnel  into  the  gold-bearing  gravel ;  and  hydraulic 
diggings  are  those  in  which  water  under  pressure  is 
used  to  disintegrate  the  gravel. 

A  ground-sluice  is  a  trench  cut  through  the  bed 
rock.  The  roughness  of  the  natural  floor  serves  for 
riffles.  Booming  is  a  process  requiring  a  large  accu- 
mulation of  water  in  a  reservoir,  which  may  be  dis- 
charged at  once,  and  carry  all  the  material  that  has  col- 
lected below  the  pass,  with  one  full  tide,  into  the 
sluices.  This  practice  is  extremely  ancient;  Pliny 
mentions  it  in  his  Natural  History. 

Deep  mining  may  be  divided  into  drifting  and  hy- 
draulic mining.  In  the  former  the  metal  is  won  by 
means  of  tunnels  and  drifts  or  horizontal  passageways 
along  the  length  of  the  deposit.  It  is  usually  resorted 
to  in  districts  where  a  flow  of  lava  has  covered  the 
gold-bearing  gravel,  and  made  hydraulic  mining  im- 
possible. It  is  followed  in  Alaska  for  another  reason, 
viz.,  because  the  constantly  frozen  ground  will  not  per- 
mit of  the  more  remunerative  method.  The  gravel  is 
carried  to  the  mouth  of  the  tunnel  and  there  dumped 
to  be  washed  in  the  sluices.  When  "cemented"  it 
must  be  broken  up  by  stamps. 


MINING.  109 

Rich  deep  placers  may  be  worked  by  drifting,  but 
whenever  practicable  hydraulicing  is  to  be  preferred  as 
giving  better  results.  It  yields  from  four  to  six  times 
the  amount  of  gold  that  drifting  does.  Thorough  ex- 
ploration should  precede  the  expenditure  of  large  sums 
in  a  hydraulic  plant.  Even  should  the  explorations 
result  in  finding  barren  gravels  the  money  will  have 
been  well  spent  in  saving  the  cost  of  an  unproductive 
plant. 

Black  sand  (magnetic  iron)  almost  always  accom- 
panies gold,  but  this  alone  is  no  sign  that  gold  is 
present,  as  black  sand  may  usually  be  obtained  by 
grinding  and  washing  crystalline  rocks. 

Ditches  and  flumes  of  wood  or  metal  are  used  to 
bring  the  water  for  hydraulic  mining  from  the  region 
where  it  was  impounded  in  a  catch  basin,  often  a  dis- 
tance of  many  miles.  It  is  said  $100,000,000  have  been 
invested  in  ditches  and  flumes,  mining  and  agricul- 
tural, in  the  western  states,  and  new  flumes  are  being 
planned  every  month.  Some  of  them  consist  of 
wrought  iron  pipe  carried  over  ravines  by  trestles  250 
feet  hig-h. 

In  planning  a  ditch  the  miner  must  see  to  it  that 
his  water  supply  is  at  a  sufficient  elevation  to  command 
the  ground.  The  more  pressure  the  water  works  un- 
der the  better.  The  supply  should  be  continuous,  or 
at  least  be  available  during  the  whole  working  season. 
Ditches  in  regions  of  deep  snow  should  have  a  south- 
ern exposure.  All  streams  crossed  by  the  ditch  should 
be  diverted  into  it,  to  counteract  leakage  and  other 
loss.  Waste  gates  must  be  provided  every  half  mile. 


no 


ABC   OF   MINING. 


HICHWATER       LEVEL 


\ 


7 


7.71    FT. 


SECTION    OF   DITCH. 


Ditches  are  better  than  flumes.  Narrow,  deep,  and 
steep  ditches  are  to  be  preferred  in  mountainous  re- 
gions, and  the  reverse  in  valleys  with  soft  soil.  Some 


cz 



_ 

't 

•fXS 

»•" 

// 

+  FT. 

\ 

r^ 

—  ' 

IJ? 

i 

ax  10' 

8  FT.  6  IN.                             \ 

SECTION  OP  FLUME. 


Californian  ditches  with  a  capacity  of  80  cubic  feet  per 
second  and  grades  of  1 6  to  20  feet  per  mile  have  been 
built. 

Sometimes  the  face  of  the  country  requires  flumes; 


MINING.  Ill 

they  may  even  be  hung  along  the  face  of  a  cliff.  In 
shattered  ground  and  where  water  is  scarce  flumes  are 
better  than  ditches.  The  grade  for  a  flume  is  usually 
25  to  35  feet  per  mile  and  its  capacity  is  smaller  than 
that  of  a  ditch.  Pine  planking  2.\  inches  by  12  to  24 
inches,  and  12  feet  long,  is  the  dimension  stuff  gener- 
ally preferred.  A  flume  2  feet  6  inches  square  requires 
posts,  caps,  and  sills  of  3x4  inch;  stringers  4x6  inch. 
Great  care  is  needed  at  curves  to  avoid  slack  water 
and  splashing.  The  boxes  must  be  shortened  and  the 
outer  side  wedged  up  until  the  water  flows  as  evenly 
as  in  the  straight  stretches.  Should  anchor  ice  form 
the  water  must  be  shut  off  at  once.  The  life  of  a  flume 
seldom  exceeds  a  dozen  years,  whereas  at  the  end  of  a 
similar  period  a  ditch  would  be  carrying  10  per  cent 
more  water  than  at  first,  owing  to  the  sides  and  bottom 
having  become  consolidated. 

Wrought  iron  pipes  are  employed  largely  in  Cali- 
fornia to  replace  ditches  and  flumes.  When  the  pipe 
crosses  a  ravine  it  is  known  as  an  inverted  siphon. 
Piping  is  also  used  to  convey  water  from  the  "pressure 
box"  to  the  "gates"  and  "nozzle."  Wrought  iron 
pipes  have  to  stand  pressure  varying  from  34  pounds 
to  800  pounds  to  the  square  inch.  Air  valves  or  blow- 
offs  must  be  provided  at  intervals  to  allow  the  escape 
of  air  from  the  pipe  while  filling,  and  to  prevent  a  col- 
lapse of  the  pipe  after  a  break.  A  covering  of  coal- 
tar  should  be  given  the  pipe  both  inside  and  out.  Cost 
varies  from  one  dollar  to  two  dollars  a  running  foot. 

The  pressure  box  ends  the  ditch  and  from  it  the 
water  passes  into  the  supply  pipe.  The  head  of  water 


112  ABC  OF   MINING. 

is  measured  from  this  point.  A  box  to  catch  sand  and 
gravel,  with  a  side  opening  and  sunk  below  the  level 
of  the  ditch,  is  called  the  "sand  box." 

One  and  a  half  inch  plank  is  generally  the  material 
out  of  which  the  pressure  box  is  made.  The  depth 
of  water  in  it  is  such  that  the  mouth  of  the  pipe  is  al- 
ways under  water..  A  grating  in  front  of  the  pipe 
catches  all  rubbish.  As  no  air  must  be  allowed  to  get 
into  the  pipe  the  water  must  be  4cept  quiet  and  deep 
at  the  pipe-head;  this  is  insured  by  dividing  the  box 
into  compartments,  the  first  receiving  the  water  and 
discharging  it  through  suitable  openings  into  the  sec- 
ond. The  water  supply  and  the  discharge  should  be 
equal.  The  water  passes  down  the  feed  pipe,  iron 
gates  distributing  it  to  the  discharge  pipes.  Water 
must  be  turned  on  gradually,  and  the  air  valves  must 
be  open.  The  piping  terminates  in  a  nozzle  with 
knuckle-joint  and  lateral  movement.  Nothing  but  the 
most  secure  bolting  to  heavy  timber  and  the  heavy 
weighting  of  the  last  length  of  pipe  should  be  relied 
upon  to  keep  the  hydraulic  giant  in  its  place.  Should 
it  once  begin  bucking  every  man  within  reach  of  the 
powerful  column  of  water  is  in  imminent  danger.  The 
nozzle  is  directed  by  means  of  a  larger  deflecting 
nozzle,  which  receives  the  impact  of  the  water  and 
causes  the  main  nozzle  to  swing  right  or  left,  up  or 
down,  as  the  case  may  demand. 

A  derrick  capable  of  moving  heavy  boulders,  and 
driven  by  water  power,  is  a  necessity  in  all  hydraulic 
mining.  Masts  100  feet  high  and  booms  90  feet  long 
are  sometimes  used,  the  motive  power  coming  from  a 


MINING.  113 

"hurdy  gurdy"  direct  impact  wheel.  Experiments 
•have  shown  that  the  bucket  has  much  to  do  with  the 
power  of  the  wheel.  For  instance,  when  the  water  im- 
pinged against  a  flat  bucket  the  efficiency  of  the  wheel 
was  less  than  45  per  cent  of  what  it  should  have  been 
in  theory,  whereas,  with  the  Pelton  bucket,  it  rose  to 
82.6  per  cent. 

There  is  a  great  amount  of  so-called  cement,  or  in 
other  words  consolidated  gravel,  in  all  the  northern 
placers,  and  in  many  California  deposits,  as  well.  In 
the  old  Cariboo  diggings  on  the  upper  Frazer,  strong 
companies  are  now  pulverizing  the  ancient  cements 
that  resisted  all  the  efforts  of  the  59  miners  with  pow- 
der and  stamp  mill,  and  are  deriving  large  profits 
therefrom. 

Black  powder  gives  even  better  results  than  dyna- 
mite in  gravel.  The  usual  allowance  of  powder  is  20 
pounds  in  weight  for  every  1,000  cubic  feet  of  ground 
to  be  moved.  Make  drifts  T-shaped,  and  tamp  the 
main  drift  almost  to  the  junction  with  the  arms,  which 
should  be  parallel  to  the  face  it  is  required  to  dislodge. 

Sluices  have  their  maximum  discharge  when  set 
straight.  Increased  grade  may  be  given  below  any 
unavoidable  curves  with  advantage,  and  the  outer  side 
of  the  sluice  must  always  be  raised.  Steps  or  "drops" 
in  the  sluices  help  in  the  recovery  of  the  gold.  In 
general,  a  grade  of  6-6^  inches  to  the  1 2-foot  box  is 
found  best;  this  is  equal  to  a  4-4^  per  cent  grade. 
Exceptional  instances  are  on  record,  however,  where 
grades  ran  from  i^  per  cent  to  8  per  cent.  In  a  4  to  7 
per  cent  grade  the  water  in  the  sluice  should  be  10 


H4 


ABC   OF   MINING. 


MINING.  115 

inches  deep  at  least.     The  following  table  gives  useful 
details : 

Sluice.                    Grade.  Water. 

6  ft.  x  36  in.  4  to  5  p.  c.  2,000  to  3,500  m.  in. 

4  ft.  X30  in.  4  p.  c.  1,800  to  2,000  m.  in. 

3  ft.  x  30  in.  i^  p.  c.  600  to  1,000  m.  in. 

'The  longer  the  better,"  is  the  sluice-builder's  motto. 
The  best  "riffles"  are  made  of  blocks  of  pine  8  to  13 
inches  deep,  wedged  into  the  bottom  of  the  sluices. 
They  are  laid  in  rows  separated  by  a  space  of  an  inch 
or  an  inch  and  a  half.  Riffle  strips  keep  them  in  posi- 
tion, these  latter  being  laid  crosswise  on  the  bottom. 
When  worn  down  to  five  inches,  the  blocks  should  be 
replaced.  This  amount  of  wear  will  probably  require 
six  months.  Stone  and  longitudinal  riffles  running 
lengthwise  of  the  box  are  often  preferred. 

An  undercurrent  is  a  broad  sluice  set  at  a  heavy 
grade  below  the  level  of  the  main  sluice.  The  fine 
stuff  drops  through  a  grating,  while  the  coarse  gravel 
continues  on  down  the  sluice. 

Refuse  material  from  quartz,  hydraulic  or  other 
mines  is  known  as  tailings.  Tailings  are  deposited  on 
a  dump,  which  in  the  case  of  a  hydraulic  claim  must 
be  sufficiently  spacious  to  receive  the  thousands  of 
yards  of  debris  deposited  on  it  each  day.  When 
available  a  narrow,  deep  canyon,  or  a  tunnel,  may 
take  the  places  of  dumps. 

Quicksilver  is  used  in  the  sluices,  14  to  18  flasks 
being  used  every  fortnight  in  a  long  sluice.  It  is 
not  placed  in  the  last  300  or  400  feet. 


Il6  ABC   OF   MINING. 

In  working,  keep  the  face  of  the  bank  "square.** 
Washing  should  be  carried  on  continuously.  Watches 
must  be  set  over  the  sluices,  or  gold  is  likely  to  be 
missed.  As  an  extra  precaution,  the  sluices  should  be 
run  full  of  gravel  before  shutting  off  the  water.  There 
is  no  fixed  custom  regulating  "clean  ups."  S(  me  man- 
agers do  so  every  20  days,  others  run  two  or  three 
months,  others  again  clean  up  but  once  in  a  season. 
In  large  operations,  the  first  2,000  feet  of  sluice  are 
cleaned  up  every  fortnight;  the  remaining  boxes  once 
a  year. 

Sluices  are  cleaned  from  the  head  downward,  the 
blocks  being  taken  up  for  that  purpose.  The  amalgam 
of  gold  and  quicksilver  is  collected  in  sheet  iron 
buckets.  The  final  step  is  reached  when  the  amalgam 
is  retorted  and  melted  in  a  graphite  crucible. 

The  principle  of  which  the  hydraulic  miner  takes 
advantage  is  the  great  specific  gravity  of  gold  as  com- 
pared with  water  and  rock.  To  illustrate  this  quality 
it  may  be  noted  that  on  a  smooth  surface  inclined  at 
an  angle  of  I  in  48,  subjected  to  a  heavy  stream  of 
water,  95  per  cent  of  the  fine  gold  in  gravel  does  not 
travel  three  feet. 

The  loss  of  quicksilver  fed  into  sluices  will  vary, 
even  under  good  management,  from  n  per  cent  to 
25  per  cent  of  the  amount  fed  to  the  boxes. 

Hydraulic  mines  under  favorable  conditions  are 
very  paying  investments.  Gravel  yielding  10  cents  a 
cubic  yard  has  been  worked  for  6  cents  a  cubic  yard, 
at  the  rate  of  a  million  cubic  yards  a  year.  On  another 


MINING.  117 

large  claim  600,000  cubic  yards  were  worked  for  6 
cents  a  cubic  yard,  yielding  13  cents  a  cubic  yard. 

River  dredging  is  another  form  of  gold  winning 
that  has  been  brought  to  a  great  state  of  perfection  in 
New  Zealand.  Although  the  dredge  has  not  yet  ac- 
quired the  importance  in  America  that  was  expected, 
it  is  successful  on  one  or  two  western  rivers,  and  as 
the  subject  becomes  better  understood  it  is  conceiv- 
able that  American  mining  engineers  will  be  as  suc- 
cessful in  devising  improved  dredges  as  they  have  been 
in  all  other  branches  of  their  profession. 

In  New  Zealand  the  bucket  dredge  has  proved  more 
satisfactory  than  the  suction  dredge,  although  a  hasty 
conclusion  would  probably  give  the  latter  the  palm. 
At  Bannack,  Mont.,  the  Bucyrus  Company  has  several 
dredges  in  successful  operation.  One  is  102  feet  long, 
36  feet  wide,  and  draws  36  inches  of  water.  It  is  very 
substantially  made,  and  weighs  nearly  700,000  pounds. 
Before  such  a  dredge  is  launched,  a  dam  is  built  across 
the  gulch  to  impound  sufficient  water.  As  the  gravel 
is  dredged  and  washed,  it  is  dumped  astern  of  the 
dredge,  which,  in  the  case  of  a  shallow  creek,  moves 
up  to  the  excavation  made  by  the  buckets.  The  boil- 
ers of  this  dredge  are  double,  and  together  have  250 
H.  P.  There  are  36  buckets,  and  each  one  has  a  hori- 
zontal drag  of  eight  feet,  a  capacity  of  five  cubic  feet, 
and  travels  at  the  rate  of  fourteen  feet  a  minute.  After 
treatment  by  trommels,  or  revolving  screens,  coppers, 
and  sluices,  and  finally  by  a  centrifugal  pump,  the  now 
almost  valueless  gravel  goes  overboard  again,  leaving 
behind  98  per  cent  of  the  gold  it  once  held. 


Il8  ABC   OF    MINING. 

The  traction  dredge  is  really  a  land-mining  machine, 
as  it  is  adapted  for  work  on  land  nearly  Mat,  where  but 
little  water  is  obtainable.  The  machine  travels  on 
bogia  tracks.  A  5O-H.  P.  boiler  supplies  the  water. 
A  boom,  40  feet  long,  carries  a  shovel  of  1.5  cubic 
yards'  capacity,  and  moves  70  cubic  yards  each  hour. 

Mr.  John  W.  Gray,  one  of  the  best  authorities,  has 
recently  written  to  the  Mining  and  Scientific  Press  of 
San  Francisco  a  most  interesting  description  of  the 
progress  made  in  saving  the  gold  from  the  streams  in 
New  Zealand.  He  says,  in  part: 

"After  great  effort,  numerous  trials,  many  failures 
and  some  large  losses,  this  system  of  gaining  gold  has 
been  evolved  from  crude  beginnings  into  a  systematic 
ana  satisfactory  method  of  mining.  Dredging  for  gold 
is  now  attracting  attention  and  bids  fair  to  become  an 
established  form  of  mining  for  that  metal.  In  Xe\v 
Zealand,  where  more  work  of  this  nature  has  been  done 
than  elsewhere,  the  evolution  of  the  industry  has  been 
the  work  of  years.  The  rivers  upon  which  dredging 
operations  are  carried  on  are  swift-flowing  streams, 
subject  to  frequent  floods,  having  a  considerable  depth 
of  gravel,  with  boulders  and  runs  of  pay  dirt  inter- 
stratified.  The  conditions  are,  therefore,  not  the  best 
for  economical  and  successful  work,  and  it  is  not  sur- 
prising that  many  failures  'have  occurred.  The  runs 
of  gold  are,  however,  often  extensive  and  rich,  and 
operations  carried  on  upon  such  reaches  have  in  a 
number  of  cases  given  satisfactory  results. 

"The  improved  form  of  dredge  is  a  double  pontoon, 
with  ladder  and  chain-bucket  arrangement  between. 


MINING.  119 

Screens  separate  the  coarse  from  the  fine  material. 
Wide  sluicing  tables  catch  the  gold,  centrifugal  pumps 
supply  the  water,  and  waste  material  is  handled  by 
elevators.  The  power  is  usually  steam,  although  elec- 
tricity is  used  in  a  few  instances,  where  conditions  are 
favorable.  The  dredges  vary  in  size  and  capacity,  but 
are  now  built  of  large  size  and  great  strength.  Twenty 
thousand  dollars  is  the  cost  of  a  large  dredge  with  all 
the  latest  contrivances.  Under  favorable  conditions, 
material  has  been  handled  without  loss  that  only  yield- 
ed a  grain  of  gold  to  the  cubic  yard.  The  real  cost 
in  actual  continued  working  is  believed  to  be  very 
much  in  excess  of  that  figure  where  average  condi- 
tions exist. 

"One  dredge  on  the  Clyde  side  of  the  Shotover, 
working  to  a  depth  of  twenty  feet  below  water  level, 
lifted  40  tons  per  hour  when  operating.  The  profit 
on  eleven  dredges  for  the  four  weeks  ending  July  24, 
1897,  was  an  average  of  $2,686  for  each  dredge. 

"So  far  in  this  country  (United  States),  with  a  few 
exceptions,  dredging  operations  for  gold  have  not  been 
financially  successful.  From  crude  beginnings,  how- 
ever, the  machines  have  been  rapidly  improved  and 
perfected,  until  now,  in  some  localities,  dredges  be- 
lieved to  be  the  most  complete  yet  constructed  are 
being  put  in  operation,  and  results  are  promised,  not 
yet  attained,  in  the  way  of  economical  working  and 
high  percentage  of  saving.  During  the  last  few  years, 
a  number  of  dredges  have  been  operated  in  California, 
British  Columbia,  Idaho,  Montana  and  Colorado,  but 
with  poor  success.  Very  few  prove  themselves  capable 


120  ABC    OF    MINING. 

of  paying  their  way.  Some  of  the  machines  were 
faulty  within  themselves,  others  were  entirely  unable 
to  cope  with  the  swift  currents  and  large  boulders  of 
the  streams  upon  which  they  were  operated.  This 
latter  is  said  to  have  notably  proved  the  case  with  the 
dredges  tried  upon  the  Frazer  and  Ouesenelle  rivers. 

"Dredging  operations  on  Grasshopper  Creek,  near 
Bannack,  Mont.,  are  now  carried  on  successfully  upon 
a  large  scale.  The  upper  Sacramento  river,  in  this 
state,  has  a  dredge  doing  profitable  work,  and,  in  a 
small  way,  dredging  is  successful  upon  the  Kzamath. 
A  dredge  upon  that  river,  composed  of  two  flat  boats 
with  a  large  steel  scoop  between,  is  able  to  out  and 
hoist  the  gravel  and  soft  bed  rock,  and  to  handle 
boulders  of  from  four  to  six  tons'  weight.  The  dredge 
is  run  day  and  night,  has  a  25-H.  P.  engine,  and  re- 
quires three  men  for  each  shift.  In  gravel  10  to  25 
feet  deep;  400  cubic  yards  can  be  handled  every  twen- 
ty-four hours.  Cost  of  dredge,  $8,000. 

"A  large  dredge  of  the  chain-bucket  variety  is  oper- 
ating in  Northern  Mexico,  in  a  dry  country,  where 
there  is  little  water.  The  actual  capacities  of  these 
machines  are  60,  100  and  150  yards  per  hour. 

"Perhaps  the  most  interesting  dredge  yet  brought 
to  the  notice  of  the  public  is  one  lately  built  by  the 
Risdon  Iron  Works,  San  Francisco,  and  now  operating 
upon  the  Yuba  river,  near  Smartsville,  Cal.  It  is  of 
the  elevator,  or  chain-bucket,  type,  96  feet  long,  com- 
posed of  two  pontoons,  separated  by  a  space  five  feet 
in  width,  in  which  is  operated  the  ladder  carrying  the 
buckets.  One  man  controls  the  dredge  by  means  of  a 


MINING.  121 

power  winch  with  six  drums.  Four  drums  carry  lines 
from  the  corners  of  the  dredge  to  anchorages  on 
shore — one  a  head-line  and  one  the  ladder  line.  The 
machine  is  to  dredge  to  a  depth  of  45  feet,  and  is 
said  to  have  a  gross  capacity  of  93  cubic  yards  per 
hour.  The  material  discharges  from  the  buckets  into 
a  revolving  and  perforated  screen.  This  segregates  the 
large  material,  which  is  then  conveyed  away  by  the  tail- 
ings elevator.  Water  (3,000  gallons  per  minute)  is  sup- 
plied to  the  revolving  screen  for  washing  and  sluicing 
purposes  by  a  centrifugal  pump,  and  the  fine  stuff  falls 
through  the  holes  in  the  screen  into  a  distributing  box, 
from  which  it  passes  to  a  set  of  gold-saving  tables  and 
thence  to  a  flume.  The  tables  are  covered  with  cocoa 
matting  and  expanded  metal.  The  top  tumbler  of 
bucket-chain  is  operated  by  a  vertical  compound  con- 
densing engine  indicating  35  H.  P.,  which  also  op- 
erates the  pump.  It  is  claimed  for  this  dredge  that  in 
any  ground  not  deeper  than  60  feet  below  water  level 
or  more  than  20  feet  above,  and  which  contains  boul- 
ders of  not  more  than  one  ton  weight,  the  material  can 
be  handled  at  from  3  to  5  cents  per  cubic  yard.  If 
the  capacity  of  the  machine  is  given  without  deduction 
for  water  raised,  imperfect  filling  and  general  delays, 
and  the  increase  in  volume  of  the  gravel  when  broken 
up  in  filling  the  buckets,  the  actual  working  capacity 
would  be  less,  and  from  these  causes  and  the  losses 
from  wear  and  tear,  breakages  and  repairs,  the  cost  of 
operating  would  be  increased.  The  cost  of  the  dredge 
complete  upon  the  river  is  said  to  have  been  $25,000. 
"In  the  evolution  of  the  dredge  into  the  elevator  or 


122  ABC   OF    MINING. 

chain-bucket  machine,  now  the  popular  form,  the  vari- 
ous kinds  of  dredges  were  given  trials.  The  dipper 
dredge  is  not  adapted  to  dredging  for  gold,  and  some 
of  the  gold  is  lost.  With  agitation  of  the  gravel  the 
gold  soon  settles  and  is  not  recovered.  It  is  also  very 
difficult,  if  not  impossible,  to  construct  a  dipper  dredge 
that  is  water-tight.  Another  objection  is  that  the  ma- 
terial is  supplied  intermittently,  thus  making  necessary 
certain  undesirable  arrangements  for  supplying  the 
material  in  a  continuous  flow  to  the  gold-saving  tables. 
The  same  objections  apply  with  greater  force  to  the 
clam-shell  form  of  dredge.  It  is  by  no  means  water- 
tight, and  loses  most  of  the  gold  in  the  act  of  dredg- 
ing and  bringing  up  the  gravel.  The  objections  would 
seem  not  to  have  the  same  force  if  applied  to  hard 
cemented  gravel  or  to  gravel  with  sufficient  clay  or 
other  binding  material  to  make  it  consistent.  It  is 
well  to  remember  that  these  forms  of  dredges  are,  in 
many  positions,  economical  of  operation. 

"The  hydraulic  dredge  has  had  fair  trials  and  proved 
a  failure.  Large  storms  greatly  lessen  the  efficiency 
of  this  form  of  dredge,  and  numerous  boulders  hamper 
the  pumping  work.  The  suction  force,  being  intense 
near  the  pipe  and  decreasing  rapidly  a  short  distance 
away,  causes  the  sand  and  gravel  to  be  carried  off, 
leaving  the  gold  behind.  A  centrifugal  pump  is  there- 
fore of  little  use  to  catch  coarse  gold,  or  to  clear  a  hard, 
uneven  bottom.  Cutters  do  not  remove  the  trouble, 
since  the  gravel  is  dispersed  by  the  cutting,  and  the 
gold  is  separated  therefrom. 

"These  objections  would  not  obtain  under  certain 


MINING.  I2J 

conditions,  and  it  would  seem  quite  possible  that  con- 
ditions might  be  found  existing  where  the  suction 
dredges  might  be  arranged  to  do  good  work.  A  dredg- 
ing company  is  now  constructing,  at  Seattle,  two 
dredges  of  the  suction  type  to  operate  upon  the  Yukon 
river.  This  would  indicate  that  there  are  those  who 
believe  that  deposits  occur  in  and  along  that  river 
which  can  be  successfully  worked  in  this  way. 

"The  chain-bucket  machine,  the  popular  form  for 
operating  under  average  conditions,  is  a  combination 
of  the  following  elements:  An  excavating  apparatus 
which  clears  the  bottom  and  handles  the  material  with 
little  agitation  and  slowly  and  continuously  delivers 
a  regular  quantity  of  gravel  to  the  gold-saving  appli- 
ances; revolving  screen  to  receive  and  wash  the  ma- 
terial and  separate  the  coarse  from  the  fine ;  an  elevator 
or  contrivance  for  carrying  off  the  coarse  gravel  and 
stones;  gold-saving  arrangements,  or  tables,  over 
which  the  fine  material  passes  and  upon  which  the  gold 
is  caught;  a  pumping  apparatus  to  supply  water  for 
washing  and  sluicing. 

"The  proper  capacity  of  a  machine  seems  to  be 
regulated  by  the  capacity  of  the  gold-saving  appliances. 
The  tables  should  be  as  wide  as  possible,  with  frequent 
drops,  and  the  fine  material  should  be  distributed  over 
the  tables  in  a  thin  film.  The  tables  are  covered  with 
plush  or  cocoa  matting,  and  sufficient  water  supplied 
to  keep  the  material  clear.  The  material  should  be 
supplied  evenly,  continuously,  and  regularly  to  the 
tables.  Care  and  attention  are  required  to  catch  the 
fine  gold.  A  disregard  of  the  foregoing  directions  re- 


124  ABC   OF   MINING. 

suits  in  great  loss,  more  particularly  in  the  fine  gold. 
Mechanical  skill  is  required  to  properly  design  and 
construct  a  dredge,  and  the  care  of  a  competent  me- 
chanic is  necessary  to  see  that  the  machine  is  kept  in 
order  and  economically  operated.  The  saving  of  the 
gold,  however,  is  what  makes  dredging  operations  a 
commercial  success.  A  man  skilled  in  these  matters 
should  be  in  charge  of  running  operations.  Dredges 
should  be  built  of  determined  capacities,  and  should  be 
designed  to  suit  the  conditions  under  which  they  are 
to  operate.  Careful  examination  and  investigation  of 
the  ground  to  be  worked  should  be  made  beforehand, 
and  the  surrounding  conditions  studied,  and  it  goes 
without  saying  that  these  matters  require  engineering 
skill  and  experience. 

'The  field  for  dredging  for  gold  seems  large.  Where 
the  proper  conditions  exist,  it  is  a  system  which  com- 
mends itself,  and  which  gives  promise,  in  competent 
hands,  of  being  an  economical  method  of  mining. 
There  is  probably  a  very  large  extent  of  country  where 
dredging  for  gold  will  be  carried  on  profitably.  The 
ground  need  not  be  in  a  river,  if  there  is  seepage  water 
sufficient  to  float  the  dredge  and  supply  clear  water 
for  the  saving  of  the  gold.  Dredging  requires  little 
water  as  compared  with  that  required  for  sluicing  and 
elevating,  and  this  water  can,  in  many  dry  localities, 
be  supplied  at  small  expense,  where  a  supply  for  hy- 
draulic work  or  elevating  would  cost  a  very  large  sum, 
or  be  impossible  at  any  cost.  Any  power  suitable  for 
driving  the  prime  motors  can  be  utilized  to  run  the 
dredge.  Indeed,  it  would  seem  as  if  a  system  of  min- 


MINING.  125 

ing  was  about  to  be  perfected  which  may  make  possi- 
ble the  profitable  working  of  many  deposits  not  easy 
to  be  worked  by  other  methods,  and  which  may,  in 
many  instances,  solve  problems  regarding  the  success- 
ful working  of  deposits  which  hitherto  have  seemed 
most  perplexing  and  even  impossible  of  solution.  Some 
doubt  exists  as  to  possible  economical  dredging  oper- 
ations under  the  water  of  torrential  streams.  The 
strong  currents,  the  frequent  floods,  and  many  large 
boulders  found  in  the  channels  of  such  streams  make 
the  working  of  the  machines  difficult  and  costly.  This 
would  not  be  so  much  the  case  in  the  long  stretches 
of  less  current,  nor  would  it  be  so  at  all  in  the  valley- 
like  reaches  in  the  lower  portions  of  rich  streams,  nor 
in  the  wide,  flat  portions  of  country  where  the  streams 
enter  the  plains." 

Very  few  gold-bearing  lodes  contain  nothing  but 
free  gold ;  on  the  contrary,  they  carry  the  bulk  of  their 
values  in  the  form  of  sulphurets,  having  more  or  less 
gold  incorporated,  and  even  when  the  gold  is  native 
and  free-milling  at  the  surface,  it  is  generally  changed 
into  sulphurets  as  depth  is  gained.  So  the  miner  has 
to  consider  methods  of  recovery  more  complicated  and 
expensive  than  simple  amalgamation  with  mercury,  for 
upon  gold  included  in  pyrites  mercury  has  no  effect. 
Titanic  iron,  hematite,  and  tungstate  of  iron  often 
hold  gold,  or  soft  clay  ores  carry  it  in  their  midst,  and 
such  combinations  tax  all  the  skill  of  the  mining  en- 
gineer merely  to  save  a  respectable  percentage  of  the 
assay  value.  Sometimes  chlorination  and  sometimes 
cyanization  are  the  measures  tried,  but  supposing  the 


126 


ABC    OF    MINING. 


preliminary  treatment  to  have  been  by  stamps  in  the 
battery,  concentrating  is  one  of  the  main  reliances  of 
the  mill  man.  The  blanket  table  is  undoubtedly  the 
oldest  type  of  concentrating  machine,  but  it  is  very 
inferior  to  modern  inventions.  Percussion  tables  often 
do  good  work.  In  this  system  a  sharp  and  frequently 
repeated  blow  is  given  the  table,  in  such  fashion  as  to 
make  the  heavy  material  separate  from  the  light. 
"Shaking"  and  "rocking"  tables  are  favored  in  some 
mills,  and  they  give  better  results  on  fine  gold  than 


FRUE  VANNER. 

any  of  the  previously  mentioned  devices.  But  the  best 
machine  so  far  invented  is  the  Frue  Vanner — an  end- 
less rubber  band  drawn  over  an  inclined  table,  having 
both  revolving  and  side  motions.  The  lighter  particles 
are  carried  off  by  water,  and  the  heavier  collected  in  a 
trough. 

Veins,  lodes,  or  ledges,  may  be  found  in  stratified 
or  unstratified  rocks,  and  in  the  former  they  generally 
cut  the  beds  at  an  angle.  Veins  are  bounded  by  walls. 
The  rock  in  which  a  vein  is  found  is  a  country  rock. 
Smooth  walls  are  called  "slickensides."  The  upper 


MINING.  127 

wall  of  an  inclined  vein  is  the  hanging  wall ;  the  other 
the  foot  wall.  A  layer  of  clay  between  the  veins  and 
wall  is  a  selvage.  A  mass  of  rock  enclosed  in  the  vein 
is  a  horse.  The  vein  stone,  or  gangue,  is  all  that  part 
of  a  vein  that  is  not  mineral. 

The  throw  of  a  fault  in  a  vein  is  measured  by  the 
amount  of  vertical  displacement.  When  the  miner 
comes  to  a  fault,  he  should  follow  the  greater  angle  in 
his  attempt  to  recover  the  lode.  For  instance,  on  min- 


A  FAULT. 

ing  along  A  B  to  the  line  of  fault  X  Y,  the  exploration 
will  be  continued  downward,  because  the  angle  A  B  Y 
is  greater  than  the  angle  A  B  X. 

Mercury  that  has  been  "sickened,"  that  is  to  say, 
has  lost  its  brightness  and  power  of  amalgamating, 
may  often  be  cured  by  washing  with  an  extremely  weak 
solution  of  sulphuric  acid  and  adding  a  little  zinc. 

As  regards  the  comparative  merits  of  chlorination 
and  cyanization,  it  may  be  said  the  one  is  the  equal  of 
the  other.  Under  certain  conditions,  chlorine  gives  a 
higher  percentage  of  gold ;  under  others  the  same  may 
be  said  of  cyanide.  A  description  of  either  process 


128  ABC  OF   MINING. 

would  be  out  of  place,  however,  in  a  simple  elementary 
work. 

Handed  down  through  the  centuries,  the  primitive 
arrastra  is  still  useful  in  certain  contingencies.  It  is 
like  a  cider  mill  in  its  principle,  and  was  probably  sug- 
gested by  recollections  of  that  machine,  or  else  of  the 
Spanish  wine-press.  A  circular,  shallow  pit,  a  dozen 
feet  or  more  in  diameter,  is  first  paved  with  hard,  un- 
cut stones  of  granite,  basalt,  or  other  hard  rock.  This 
pavement  is  a  foot  thick,  and  beneath  it  is  a  bed  of 
puddled  clay  6  inches  deep.  A  vertical  shaft  with  an 
arm,  or  arms,  revolves  in  the  center  of  the  arrastra. 
Grinding  blocks  weighing  400,  or  perhaps  even  1,000 
pounds,  are  fastened  to  the  arms  by  chains  or  rawhide 
strips.  The  forward  part  of  each  stone  is  raised  a 
couple  of  inches  off  the  floor.  Mule,  horse,  water  or 
steam  power  may  be  used,  the  speed  ranging  from  4 
to  18  turns  a  minute. 

Nothing  can  be  simpler,  less  expensive,  or  save 
a  greater  proportion  of  the  value  in  the  ore  than  the 
arrastra.  Its  limited  capacity  is  its  worst  fault.  An 
arrastra  10  feet  in  diameter  will  treat  500  or  600  pounds 
of  ore  at  a  charge,  and  handle  one  ton  a  day  of  24 
hours.  Ores  that  were  so  poor  they  yielded  nothing 
to  the  stamp  mill  have  paid  well  with  the  arrastra. 

This  humble  device  may  be  used  to  advantage,  prob- 
ably in  some  of  the  poorer  gold-bearing  cemented 
gravels  of  the  Northwest.  The  ore  should  be  crushed 
to  pigeon-egg  size.  Small  quantities  of  mercury,  about 
a  tablespoonful  to  every  five  tons  of  gravel,  has  been 
found  a  satisfactory  proportion  in  California. 


MINING.  129 

In  a  permanent  arrastra  a  layer  of  neatly-dressed 
and  pointed  stones  is  laid  in  hydraulic  cement.  A  fair- 
sized  arrastra  will  require  50  pounds  of  quartz  to 
charge  it,  and  the  material  must  be  broken  into  pigeon- 
egg  size.  After  the  machine  has  been-  started,  and  a 
little  water  added  from  time  to  time,  little  else  need  to 
be  done  for  four  or  five  hours,  and  this  is  perhaps  one 
of  the  reasons  for  which  it  has  always  been  so  favored 
in  indolent  Mexico.  At  this  stage,  the  quartz  and  ore 
will  be  very  finely  pulverized,  and  water  should  be  add- 
ed until  the  pulp  is  as  thin  as  cream.  Quicksilver  must 
now  be  added  in  the  proportion  of  ij  ounce  for  every 
supposed  ounce  of  gold  in  the  ore  being  treated.  Two 
hours'  further  grinding  is  given,  and  water  then  ad- 
mitted until  the  paste  is  quite  thin,  the  speed  of  the 
arrastra  being  reduced  at  the  same  time  so  as  to  allow 
the  amalgam  and  quicksilver  to  sink  to  the  bottom.  A 
half  an.  hour  of  this  treatment  suffices  and  the  thin 
mud  is  run  off,  leaving  the  gold  and  amalgam  on  the 
floor  of  the  arrastra.  A  second  charge  of  broken  quartz 
is  put  in  and  the  operation  repeated,  the  clean-up  not 
taking  place  oftener  than  every  ten  days,  and  some- 
times only  at  intervals  of  a  month  or  so.  The  rougher 
the  bottom  the  longer  the  interval  between  clean-ups, 
as  all  the  stone  work  must  be  taken  up  each  time  and 
all  the  sand  and  mud  between  them  must  be  washed 
carefully.  The  arrastra  is  extremely  valuable  to  the 
poor  man  who,  having  discovered  a  gold-bearing  vein, 
wishes  to  transfer  some  of  the  metal  into  his  own 
pocket,  at  the  least  possible  outlay.  Its  cheapness 
places  it  within  reach  of  all,  while  a  stamp  will  cost  a 


130  ABC   OF   MINING. 

good  deal.  Then  again  the  amalgamation  being  more 
perfect  in  the  arrastra  than  in  any  other  mill,  it  is  par- 
ticularly suited  for  the  poor,  lean  ores.  It  is,  however, 
only  adapted  to  those  that  are  free-milling,  others  not 
being  suited  to  this  form  of  apparatus,  nor,  indeed,  to 
any  save  very  costly  plants.  Some  arrastras  have  been 
built  to  treat  old  tailings,  and  have  paid  well  when 
water  power  could  be  used.  Free-milling  gold  and 
high-grade  silver  and  gold  ores  are  those  usually 
treated. 

The  flagging  should  be  of  tough,  coarse  rock ;  gran- 
ite, basalt  or  compact  quartz  are  all  good.  This  flag- 
ging should  be  at  the  very  least  a  foot  thick.  When 
the  arms  of  a  lo-foot  arrastra  are  revolving  14  times 
a  minute,  the  outer  stone  is  traveling  400  feet  a  minute. 
Round  holes  closed  by  wooden  plugs,  or  a  side  gate, 
lets  the  liquid  mud  out.  Some  mill  men  use  chemicals 
in  the  arrastra;  potassium  cyanide,  and  wood  ashes 
or  lye  are  probably  the  most  useful,  as  the  latter  cuts 
grease  and  the  former  gives  life  to  the  quicksilver. 
Rich  silver  ores  are  treated  with  blue  stone  and  salt. 
When  the  pulp  has  been  ground  sufficiently,  quick- 
silver is  added,  sometimes  250  pounds  being  put  in  a 
single  charge.  A  1 2-foot  arrastra  will  never  treat  more 
than  two  tons  a  day,  and  often  no  more  than  one-half 
that.  One  man  a  shift  can  look  after  a  couple  of  ar- 
rastras, and  the  owner,  in  case  of  one  arrastra  that  is 
working  on  tailings,  often  does  everything  himself. 
Overshot  wheels,  or  turbines,  or  hurdy-gurdies,  furnish 
the  power  in  many  cases.  A  simple  mule-power  ar- 
rastra may  be  built  for  $150. 


MINING.  131 

A  side  hill  should  be  chosen  for  the  site  of  a  battery. 
Ample  water  power  is  necessary,  though  provision  may 
be  made  for  saving  it  in  catch  basins  should  such  a 
course  be  desired.  Moreover,  there  must  be  plenty  of 
room  below  the  mill  for  the  tailings,  as  it  may  be  de- 


STAMP  BATTERY. 

sirable  at  some  future  time  to  put  them  through  a 
second  course  of  treatment. 

Automatic  ore-feeders  are  always  put  in  by  good 
mill  men.  In  cold  climates  the  water  that  goes  through 
the  mill  should  be  heated,  and  this  may  be  done  by  the 
exhaust  steam,  but  care  is  necessary  that  no  grease  get 
into  it,  as  it  would  prevent  the  gold  from  amalgama- 


132  ABC   OF   MINING. 

ting.  The  stamps  for  a  light  mill  may  be  3  or  5  in 
number,  and  weigh  from  700  to  850  pounds.  Tables 
must  be  water-tight,  with  half  an  inch  to  one  inch  drop 
to  the  foot,  according  to  the  fineness  of  the  gold.  Be- 
low them  tables,  having  the  same  inclination  and  cov- 
ered with  blanketing,  are  used  to  retain  specks  of  gold 
that  have  passed  over  the  plates  without  amalgama- 
ting. 


THREE    STAMP   BATT1 

After  the  concentrated  materials,  always  spoken  of 
as  the  concentrates,  have  passed  over  the  tables,  they 
are  often  roasted  to  get  rid  of  the  sulphur,  arsenic,  etc., 
and  afterwards  treated  with  quicksilver  in  the  pan,  or 
tin,  with  chlorine  or  cyanide.  These  processes  belong, 
however,  to  the  domain  of  the  professional  chemist 
and  metallurgist,  and  require  the  knowledge  and  ex- 
perience of  an  expert  to  stand  a  chance  of  success. 


MINING.  133 

The  coarseness  of  the  mortar  screens  is  subject  to 
infinite  variety,  according  to  individual  preference. 
The  number  of  holes  to  the  square  inch  ranges  be- 
tween 60  and  800  in  Australia,  and  between  900  and 
10,000  in  the  United  States.  The  holes,  when  round, 
agree  in  numbers  with  those  of  sewing-machine 
needles,  from  o  to  10.  When  slots  are  preferred  to 
holes,  they  are  generally  f-inch  in  length  and  No.  6 
diameter.  Russia  sheet  iron,  or  sheet  steel  i -32-inch 
thick  is  the  material  of  which  they  are  made.  It  should 
weigh  one  pound  to  the  square  foot,  be  very  soft  and 
tough,  have  a  clean,  smooth  surface,  and  show  no  rust 
or  flaws.  In  Australia  1-16  sheet  copper  is  preferred. 
The  holes  in  any  case  must  be  punched  in  the  sheet 
so  that  the  rough  edges  are  turned,  and  thus  any  pulp 
that  finds  its  way  into  one  of  the  holes  is  certain  to 
get  out  again  and  not  clog.  A  battery  may  require  13 
sets  of  screens  a  year;  each  screen  having  a  surface 
of  about  1 1  square  feet.  Russia  iron  screens  endure 
15  to  40  days.  As  the  work  a  stamp  can  do  depends 
entirely  upon  how  much  pulp  can  escape  through  the 
screen  in  any  given  tim,e,  the  latter  is  evidently  a  very 
"important  detail  of  a  battery. 

Prospecting  stamp  batteries  differ  from  ordinary  bat- 
teries, chiefly  in  being  of  light  build  and  weight. 

Amalgam  coming  from  battery  stamps  is  often  mixed 
with  all  sorts  of  rubbish.  After  being  gathered,  it  is 
dried  with  a  sponge,  foreign  matter  picked  off  the  sur- 
face and  clean  quicksilver  added.  Soft  unglazed  paper 
thrust  into  the  mercury  removes  the  last  vestiges  of 
water,  and  then  a  card  is  drawn  vertically  or  a  piece 


134  ABC   OF   MINING. 

of  blanket  horizontally  across  the  mercury  to  clean  it 
of  iron.    After  squeezing,  the  amalgam  is  retorted. 

All  the  amalgam  is  placed  in  one  large  kettle  and,  if 
possible,  the  latter  is  put  on  a  strong  table  having  an 
inclined  surface  with  a  groove  and  hole  at  the  lower 
end  to  catch  any  stray  globules  of  quicksilver.  Sodium 
amalgam,  one  ounce  to  each  75  pounds  of  mercury,  is 
put  in  the  amalgam  kettle  and  the  whole  stirred.  This 
sodium  amalgam  is  not  absolutely  necessary,  but  is 


GOLD  RETORT. 


desirable.  After  some  minutes,  water  is  poured  on  the 
mercury  and  the  whole  stirred.  All  dirt  rises  to  the 
surface  and  is  removed  with  a  sponge.  The  cleaning 
is  continued  until  the  mercury  seems  absolutely  free 
from  any  impurity,  when  it  is  dried  with  a  sponge.  It 
is  next  turned  into  pointed  bags  of  stout  canvas  and 
force  applied  until  most  of  the  quicksilver  has  squeezed 
through.  The  amalgam  remains  behind.  The  quick- 
silver still  contains  some  gold,  but  it  had  better  remain 


MINING.  135 

if  the  mercury  is  to  be  used  again,  as  gold  attracts 
gold;  it  can  always  be  recovered  by  retorting. 

Sodium  amalgam  is  best  made  by  the  miner  himself, 
enough  for  one  clean-up  at  a  time.  Metallic  sodium 
and  quicksilver  are  the  necessary  ingredients;  the 
former  being  kept  in  a  wide-mouthed  bottle  covered 
with  coal  oil.  A  frying-pan  makes  a  useful  mixer.  It 
must  be  dry  and  clean.  Five  pounds  of  clean  mercury 
is  poured  into  the  pan,  and  dried  with  a  sponge,  and 
heated  beyond  the  boiling-point  of  water,  but  not  much 
above,  or  there  will  be  a  sensible  loss  of  mercury.  A 
piece  of  sodium  is  wiped  dry,  cut  into  ^-inch  squares 
and  placed  with  a  long  pair  of  tongs  in  the  cenfer  of 
the  warm  quicksilver,  which,  by  the  way,  is  now  off  the 
fire  and  in  the  open  air,  the  operator  meanwhile  keep- 
ing religiously  to  windward  of  it,  unless  he  courts  sali- 
vation and  all  its  attendant  ills.  As  soon  as  the  sodium 
touches  the  mercury  a  flash  and  mild  explosion  will 
follow,  but  after  a  few  cubes  have  been  introduced  into 
the  frying-pan,  always  in  the  center,  this  will  cease. 
As  soon  as  a  solid  mass  of  amalgam  forms  in  the 
middle  of  the  pan,  the  contents  must  be  stirred  slowly, 
and  a  little  more  sodium  added.  The  whole  mass  now 
crystallizes  out,  and  if  put  into  closely-stopped  bottles 
it  will  keep  without  further  protection  for  a  little  time. 
Once  opened,  each  bottle  must  be  used.  Observe  all 
these  directions  faithfully,  then  there  will  be  no  danger 
of  inhaling  mercurial  fumes  nor  of  being  blown  to 
atoms.  After  the  amalgam  is  once  made,  it  is  safe  as 
sugar. 

In  retorting  amalgam  never  fill  the  flask  too  full, 


136 


ABC   OF    MINING. 


and  apply  the  heat  gradually,  and  always  from  the  top 
of  the  flask  downward. 

The  rocker  is  a  box  40  inches  long,  16  inches  wide 
on  the  bottom,  sloped  like  a  cradle,  and  with  rockers 
at  each  end. 

A  hopper  20  inches  square  and  4  inches  deep,  having 
an  iron  bottom  perforated  with  ^-inch  'holes,  occupies 
the  top.  A  light  canvas-covered  frame  is  stretched 
under  this,  forming  a  riffle.  Riffles,  and  occasionally 


CROSS  SECTION  OF  ROCKER. 

amalgamated  copper  plates,  are  placed  in  the  bottom. 
The  gravel  is  fed  into  the  hopper,  the  cradle  being  then 
rocked  by  one  hand  while  water  is  fed  by  a  dipper  with 
the  other. 

The  cradle  must  be  placed  on  an  inclination  while 
being  worked,  and  under  the  influence  of  the  continued 
side-to-side  rocking  the  dirt  is  quickly  disintegrated, 
passes  through  the  riddle  and  falls  on  the  apron.  From 
the  apron  it  is  conveyed  to  the  inner  end  of  the  cradle 


MINING.  137 

floor,  from  which  it  flows  over  the  riffles,  or  bars,  and 
out  at  the  mouth.  The  difference  in  level  of  the  floor 
is  generally  about  2|  inches,  but  this  may  be  varied  ac- 
cording to  the  nature  of  the  dirt  treated.  Large  stones 
in  the  riddle  or  hopper  must  be  thrown  out,  but  smaller 
ones  assist  in  breaking  up  the  lumps  of  dirt.  Every 
little  while  the  pebbles  are  turned  out  and  looked  over 
for  nuggets.  Clean-ups  are  necessary  two  or  three 
times  a  day.  The  hopper  is  taken  off  first,  then  the 
apron  is  slid  out,  and  washed  in  a  bucket  or  tub  con- 
taining clean  water,  and  finally  the  gold  and  amalgam 
are  collected  in  an  iron  spoon  from  behind  the  riffle 
bars,  and  panned  out.  Gravel  requires  at  least  three 
times  its  own  weight  of  water  to  wash  it.  The  most 
convenient  way  is  to  lead  the  water  from  a  stream 
through  a  pipe  discharging  directly  over  the  hopper, 
but  this  is,  of  course,  impracticable  in  some  places. 
More  often  the  water  is  led  to  a  little  pit  on  the  right 
hand  side  of  the  operator,  from  which  he  ladles  it  up 
as  required.  One  man  can  wash  from  one  to  three 
cubic  yards  daily  according  to  the  character  of  the  dirt, 
but  every  time  'he  stops  the  machine  to  feed  it  with 
gravel  or  to  empty  the  riddle,  the  sand  will  pack,  and 
must  be  removed  before  washing  can  go  on.  Two  men 
can  wash  nearly  three  times  as  much  dirt  in  a  day  as 
one  man.  But  in  any  case,  the  rocker  is  only  a  primi- 
tive machine,  having  a  capacity  but  one-fifth  as  great  as 
that  of  the  Long  Tom,  and  but  one-tenth  that  of  a  very 
poor  sluice,  but  as  it  is  cheap,  requires  but  little  water, 
and  saves  a  high  percentage  of  coarse  gold,  the  rocker 
will  continue  to  be  used  in  many  districts. 


138  ABC    OF   MINING. 

The  Long  Tom  was  invented  many  years  ago  by 
Georgia  miners. 

It  is  a  trough  12  feet  by  15  to  20  inches  at  the  upper 
end,  and  30  inches  at  the  lower,  and  8  inches  deep. 
The  grade  is  usually  I  in  12.  A  sheet  iron  plate  forms 
the  lower  end  of  the  trough.  These  figures  refer  to  the 


L.ONG  TOM. 

upper  trough.  The  lower  or  riffle-box  is  12  feet  long 
by  3  feet  wide,  with  a  fall  equal  to  that  of  the  trough 
and  a  sufficient  depth  to  keep  the  material  and  water 
from  spilling  over  the  sides.  It  should  have  four 
riffles.  For  this  means  of  saving  the  gold,  to  work 
satisfactorily,  the  metal  must  be  coarse  and  the  water 
plentiful. 


SLUICE  BOXES. 

Every  sluice  is  an  inclined  channel  through  which 
flows  a  stream  of  water,  carrying  away  all  the  lighter 
matter  thrown  into  it,  and  separating  it  from  the  heavy. 
When  the  operations  would  not  be  permanent  enough, 
or  sometimes  for  other  reasons,  a  ground  sluice  is  pre- 
ferred to  the  ordinary  box  sluice  made  of  boards. 


MINING.  139 

Ground  sluicing  requires,  however,  six  times  as  much 
water  as  does  a  box  sluice  to  do  the  same  amount  of 
work.  It  is  simply  a  gutter  in  the  bed  rock,  and  if  the 
bottom  is  hard  and  uneven  its  inequalities  will  arrest 
the  gold ;  if  not,  a  number  of  boulders  too  heavy  to  be 
moved  by  the  stream  are  put  into  the  sluice  to  act  as 
riffles.  No  mercury  is  used.  The  water  is  turned  off 
and  the  collected  coarse  gold  washed  in  the  pan. 

Sluice  boxes  may  be  any  length,  from  30  to  5,000 
feet.  They  vary  in  width  from  I  to  5  feet,  though 
generally  16  or  18  inches.  The  grade  is  proportioned 
to  the  fineness  of  the  gold,  varying  from  8  inches  to 
2  feet  to  the  1 2-foot  box  or  length.  The  bottom  should 
be  of  i^-inch  plank,  and  the  sides  of  i-inch  boards. 
The  boxes  are  made  4  inches  wider  at  the  upper  end 
than  at  the  lower,  so  as  to  telescope. 

The  best  method  found  yet  for  arresting  fine  gold 
is  the  copper  plate  amalgamated  with  mercury  on  its 
face.  These  plates  are  never  used  at  the  head  of  a 
sluice  or  other  situation  where  there  is  much  coarse 
gold,  as  they  would  be  superfluous  in  such  a  situation, 
but  are  placed  some  distance  down  the  sluice  and  are 
most  efficacious  in  arresting  the  "flour,"  or  excessively 
fine  gold.  Plates  are  always  of  copper  above  1-16  inch 
thick,  and  may  be  6  feet  or  more  long,  and  of  a  width 
suited  to  the  capacity  of  the  sluice.  When  treated 
with  quicksilver,  they  become  as  brittle  as  glass,  and 
must  be  handled  with  care.  The  copper  plate  is  first 
washed  with  a  weak  solution  of  nitric  acid,  and  then 
mercury  that  has  been  treated  with  a  weak  nitric  acid 
solution  is  rubbed  on  the  plate.  As  this  surface  of 


HO  ABC   OF    MINING. 

quicksilver  wears  off,  it  may  be  replaced  by  a  little 
fresh  mercury.  Any  green  slime  on  a  plate  is  an  evi- 
dence of  copper  salts  in  the  water.  It  must  be  scraped 
off  and  the  spot  rubbed  with  fresh  quicksilver.  Gold 
attracts  gold,  therefore  the  plates  should  not  be  cleaned 
up  too  often. 

.Copper  plates  may  be  freed  from  gold  by  heating 
them  over  a  fire  and  causing  the  quicksilver  to  evapor- 
ate slowly.  The  plates,  after  being  cooled,  are  rubbed 
with  dilute  muriatic  acid  and  covered  with  damp  cloths 
for  one  night.  They  are  then  rubbed  with  a  solution 
containing  salt  peter  and  sal  ammoniac,  and  once  more 
heated  over  some  hot  coals,  but  not  allowed  to  get  red 
hot.  Soon  the  gold  scale  rises  in  blisters;  the  plates 
are  then  removed  from  the  fire  and  scraped.  Those 
parts  of  the  plates  that  have  not  yielded  up  their  gold 
must  be  re-treated  and  fired  until  they  do  so.  All  these 
scales  of  gold  are  then  collected  in  a  porcelain  dish, 
the  base  metals  are  dissolved  out  with  nitric  acid,  and 
the  gold  is  then  smelted.  Corrosive  sublimate  should 
be  placed  in  the  crucible  as  long  as  any  blue  flame 
is  seen  to  come  from  it. 

Some  mill  men  prefer  to  amalgamate  their  copper 
plates  with  silver  amalgam,  claiming  that  silver-coated 
plates  save  a  higher  percentage  of  gold.  To  amal- 
gamate in  this  way  take  some  silver  bullion,  or  silver 
coin,  and  dissolve  in  weak  nitric  acid,  only  just  strong 
enough  to  act  upon  the  silver.  (If  you  use  too  much 
nitric  acid  you  will  waste  mercury  and  make  the  amal- 
gam harder  than  it  should  be  for  the  best  results.)  After 
crystals  have  formed,  quicksilver  must  be  added,  heat- 


MINING.  141 

ing  gently  meanwhile,  until  a  thick,  pasty  amalgam 
has  formed.  Let  this  new  compound  stand  for  some 
hours,  and  squeeze  through  chamois  as  usual.  The 
proportion  of  silver  may  be  about  I  ounce  to  the  square 
foot  of  copper  to  be  plated. 

In  facing  new  copper  plates  with  this  amalgam,  they 
should  be  washed  first  with  dilute  nitric  acid ;  then  in 
clear  water;  the  ball  of  amalgam  being  rubbed  over 
their  surfaces,  some  little  force  being  applied.  Plates 
should  not  be  used  for  24  hours  after  coating.  Porous 
copper  plates  of  the  best  quality,  and  not  too  heavily 
rolled,  should  be  used.  Follow  the  amalgam  with  a 
swab,  and  rub  the  alloy  well  into  the  plate. 

Zinc  amalgam  (preferable  when  mine  water  contain- 
ing sulphuric  acid  is  used  in  the  battery)  is  applied  to 
the  plate  after  it  has  been  cleaned  with  a  moderately 
dilute  mixture  of  sulphuric  acid  and  water.  The  zinc- 
quicksilver  ball  is  rubbed  in  and  applied  while  the  plate 
is  still  wet.  Zinc  amalgam  is  pfepared  as  follows :  Cut 
zinc-sheet  into  small  pieces;  wash  in  weak  sulphuric 
acid;  and  dissolve  in  mercury.  When  the  quicksilver 
will  take  no  more  zinc,  squeeze  through  chamois  and 
rub-  in.  Zinc-coated  plates  should  stand  a  week  before 
being  used.  Very  weak  sulphuric  acid  will  always 
clean  these  plates  of  any  scum  that  may  form  before 
they  have  received  a  gold  coat. 

Sometimes  the  miner  will  be  troubled  with  impure 
gold  after  retorting.  If  the  metal  is  very  dark  this 
shade  may  come  from  the  presence  of  large  amounts 
of  iron.  A  heavy  proportion  of  mineral  salts,  such  as 
chloride  of  calcium  (CaCl),  sodium  (NaCl),  and  mag- 


142  ABC   OF   MINING. 

nesium  (NgG2),  in  the  battery  water  sometimes  ac- 
counts for  this.  In  such  cases  amalgamate,  retort,  pul- 
verize and  roast.  Then  smelt  with  borax,  the  iron 
passing  into  the  slag.  If  necessary  smelt  a  second  time, 
when  the  gold  should  be  pure  enough  to  dispose  of. 
In  extreme  cases,  the  gold  may  weigh  but  one-fifth  of 
the  amalgam  treated. 

In  districts  where  sufficient  water  for  sluicing  is  not 
procurable,  dry  washing  is  resorted  to.  Nothing  but 
rich,  coarse  gold  can  be  worked  by  this  method,  and 
the  dry  washer  rarely  delves  far  below  the  surface 
for  his  gold.  In  the  Mexican  deserts  the  dirt  is  laid 
on  raw  hide,  all  the  large  pebbles  picked  out  ami  the 
sand  rubbed  as  fine  as  possible  between  the  hands. 
The  sand  is  placed  in  a  batea  and  winnowed  by  tossing 
in  the  air,  the  lighter  material  being  blown  to  leaward 
and  the  heavy  gold  falling  into  the  batea.  A  form  of 
winnowing  machine  has  been  patented,  which  may  be 
driven  by  horse  or  hand-power,  which  is  said  to  give 
satisfaction.  It  works  by  forcing  a  strong  blast  of  air 
from  a  fan  through  a  canvas  screen.  The  inventor 
claims  that  it  will  do  the  work  of  three  men,  and  work 
dirt  for  2,\  cents  a  cubic  yard.  When  there  is  a  ten- 
dency in  the  material  to  cake,  dry  washing  is  im- 
possible. 


CAMP   LIFE.  143 


CHAPTER   VI. 

CAMP    LIFE. 

The  Indian  truthfully  observes:  "White  man  make 
heap  big  fire ;  keep  far  off.  Indian  make  little  fire ;  get 
close.  All  same."  The  small  fire  does  best  in  the  cir- 
cular tepee  tent,  made  of  canvas  or  leather,  in  use  on 
the  plains.  The  tepee  is  quite  an  institution,  but  it  is 
generally  as  full  of  smoke  as  a  kitchen  chimney,  and 
for  that  reason  cannot  truthfully  be  recommended.  In 
theory,  the  smoke  should  all  pass  out  of  the  opening 
in  the  top. 

By  using  no  second  skin  and  carefully  excluding  all 
air  from  around  the  lower  rim  of  the  tepee,  it  will  be- 
come an  admirable  place  to  cure  hams,  fish,  etc.,  by 
the  original  smoke-dried  process.  The  Scripture  de- 
clares that  he  that  tarrieth  over  the  wine  cup  has  red 
eyes  next  morning,  and  so  has  he  that  sleeps  in  a 
smoky  tepee.  Properly  made,  however,  the  tepee  is 
the  thing  where  wood  is  scarce. 

Some  original  spirits  are  said  to  have  started  for 
Dawson  City,  N.  W.  T.,  a  few  years  ago  with  bicycles 
and  push  carts.  If  these  means  of  transport  had  suf- 
ficed, the  world  would  have  learnt  something,  as  here- 
tofore a  canoe  and  a  sturdy  pair  of  legs  were  supposed 
to  help  the  wayfarer  in  that  region  better  than 
anything  else.  That  is  in  summer;  in  winter,  the 
dog-train  is  the  quickest  mode  of  travel.  In  the 


144 


ABC  OF  MINING. 


western  states  and  in  British  Columbia  pack  horses 
or  mules  do  the  most  of  the  prospector's  freighting, 
and  in  the  far  north  he  either  carries  his  outfit  on 
his  back  or  else  transports  it  by  canoe  in  summer,  or 
by  dog-train  after  the  rivers  have  frozen. 


HUDSON'S  BAT  DOG  SLED. 

No  amount  of  written  instructions  will  teach  a  man 
to  throw  a  diamond  hitch,  or  handle  a  canoe  in  swift 
water.  A  lesson  or  two  from  an  expert  will,  however, 
set  his  thoughts  in  the  right  direction,  and  in  time  he 
may  become  proficient.  Canoeing,  freighting  and 
chopping  are  three  things  that  are  best  begun  in  boy- 


TUKON   SLED  AND  HARNESS. 

hood;  no  one  ever  yet  became  marvelously  proficient 
in  any  one  of  them  that  began  after  reaching  adult  age. 
Dog  teams  are  made  up  of  from  three  to  six  dogs; 
a  full-sized  team  dragging  a  load  of  200  pounds  forty 
miles  a  day  for  a  week  at  a  time.  In  the  Hudson  Bay 


CAMP   LIFE.  145 

region  the  dogs  are  harnessed  one  behind  the  other, 
but  on  the  Yukon  each  pulls  by  a  separate  trace,  and 
the  team  spreads  out  like  a  fan  when  at  work. 

After  Christmas  the  snow-shoe  is  generally  a  neces- 
sity in  the  north.  Without  "paddles"  on  the  feet  the 
explorer  could  hardly  make  his  way  through  the 
woods,  while  with  them  on  he  sails  along  gayly,  making 
a  bee-line  over  frozen  lake  and  water  courses,  and 
taking  windfalls  and  down  timber  in  his  stride.  The 
shoe  in  vogue  in  the  forest  is  short  and  almost  round, 
and  flat,  while  that  of  the  plains  is  very  long,  upturned 
at  the  toe,  and  narrow.  There  is  a  reason  for  these 
modifications,  as  the  tyro  will  soon  find  out  should  he 
substitute  the  one  for  the  other  in  the  native  habitat 
of  either.  But  the  loop  by  which  the  shoe  is  fastened 
on  the  foot  is  always  the  same.  The  string  is  made 
of  moose  hide;  stretched,  and  greased  before  use.  Cari- 
bou, or  reindeer  hide,  makes  the  best  filling,  but  horse 
or  bull  hide  will  do  at  a  pinch.  The  frame  is  usually 
of  ground  ash,  or  some  other  tough,  hard  wood. 

A  camp  kit  of  cooking  utensils  often  begins  and 
ends  with  a  frying-pan  and  tin  kettle.  Certainly  when 
traveling  light,  these  things  should  be  the  last  to  go, 
as  with  them  all  things  are  possible,  even  to  amalgama- 
ting and  retorting  the  precious  metals.  The  frying-pan 
must  have  a  socket  instead  of  a  long  handle,  as  the 
latter  may  be  cut  from  a  bush  at  any  time.  A  low, 
broad  kettle  boils  in  less  time  than  a  deep,  narrow 
one  of  the  same  cubic  capacity. 

All    provisions    should    be    kept    in    canvas    bags. 
Matches  in  a  leather  case  or  safe,  or  in  a  corked  bottle. 
10 


146  ABC   OF   MINING. 

Blankets  are  never  kicked  off  if  sewn  up  at  foot  and 
side  into  a  sleeping  bag. 

The  existence  of  the  prospector  being  passed  in  re- 
gions where  the  so-called  benefits  of  civilization  have 
not  penetrated,  he  is  generally  a  healthy,  happy,  hope- 
ful man.  Especially,  hopeful.  I  do  not  remember 
ever  meeting  one  that  was  not  brimful  of  expectation 
and  trust  in  the  future.  Possibly  prospectors  that  have 
become  pessimistic  drop  out  of  the  ranks. 

Now  the  man  who  elects  to  dwell  with  nature  has 
only  himself  to  thank  if  he  does  not  like  his  lodgings. 
He  can  be  comfortable  or  wretched,  according  to  'his 
knowledge  of  woodcraft  and  wilderness  residence. 

Whereas  the  tyro  starts  out  with  the  avowed  inten- 
tion of  "roughing  it,"  the  veteran  is  particularly  care- 
ful to  take  matters  as  smoothly  as  he  may,  being  well 
assured  that  in  any  case  there  will  be  enough  inevitable 
discomfort  in  his  lot  to  satisfy  any  reasonable  craving. 
It  is  just  the  same  in  other  walks  of  life ;  the  sailor,  the 
trapper  and  the  soldier  each  learns  to  look  after  his  own 
comfort  and  to  seize  every  opportunity  of  making  life 
as  pleasant  as  possible. 

The  three  prime  wants  are  food,  clothing  and  shelter, 
and  their  importance  is  in  the  order  named.  Now, 
food  is  something  that  is  painfully  scarce  in  many  parts 
of  the  world,  and  one  of  the  great  problems  of  wilder- 
ness travel  is  to  provide  transport  for  the  supplies  that 
must  be  carried  from  civilization.  A  rigorous  north- 
ern climate  necessitates  a  large  consumption  of  strong, 
heat-producing  food,  while  in  the  tropics  the  explorer 
gets  along  very  comfortably  with  rice  or  an  occasional 


CAMP   LIFE.  147 

sl-jnny  fowl,  with  plantains  for  dessert,  and  plenty  of 
boiled  and  filtered  water.  Compare  such  a  diet  with 
that  of  Nansen,  the  arctic  explorer!  He  and  his  com- 
panion lived  and  waxed  fat  on  a  diet  of  lean  bear's 
meat  three  times  a  day,  washed  down  by  draughts  of 
melted  snow  water.  Moreover,  although  government 
expeditions,  provided  with  every  canned  and  potted 
luxury  the  stores  contain,  have  suffered  the  ravages  of 
scurvy,  these  two  adventurous  Norwegians,  living  on 
the  food  their  rifles  had  provided,  did  not  know  what 
sickness  meant. 

Other  travelers  have  found  that  they  fared  better 
by  copying  to  some  extent  the  manner  and  customs  of 
the  natives.  Fat  seal  blubber  gives  wonderful  resisting 
power  against  cold,  it  is  said;  while  a  mild,  unstimulat- 
mg  diet  of  rice  suits  the  liver  better  under  the  Equator 
than  the  Bass  ale  and  roast  beef  galore. 

On  this  continent  the  working  man  found  out  long 
ago  that  pork  and  beans  suits  him  nicely.  The  lumber- 
man says :  "It  sticks  to  the  ribs,"  by  which  robust,  if 
not  classical,  phrase  he  means  that  he  can  chop  longer 
without  feeling  hungry  on  pork  and  beans  than  on  al- 
most any  other  food.  The  laborer  having  found  by 
experience  that  the  side  of  a  pig  and  a  sack  of  beans 
was  a  good  combination  to  have  in  the  larder,  the  man 
of  science  after  a  couple  of  hundred  years  or  so  of  de- 
liberation confirms  the  discovery  by  announcing  that 
the  flesh  of  a  swine  mixed  with  the  fruit  of  the  bean 
contains  all  the  carbo-hydrates,  etc.,  necessary  to  sus- 
tain life.  The  moral  of  all  this  is  that  pork  and  beans 
must  not  be  forgotten  when  outfitting.  A  few  other 


148  ABC  OF  MINING. 

things  being  desirable,  the  following  list  may  be  con- 
sulted to  advantage  by  the  prospective  prospector. 
This  list  should  suffice  for  feeding  one  man  for  12 
months : 

Sugar 75  pounds. 

Apples  (evaporated) 50  pounds. 

Salt 25  pounds. 

Salt  pork 212  pounds. 

Pepper I  pound. 

Condensed  milk I  case. 

Flour 2  barrels. 

Candles    I  box. 

Matches 12  boxes. 

Soap   i  doz.  bars. 

Tea £  case. 

Beans 200  pounds. 

The  dictates  of  fashion  being  unheard  on  the  moun- 
tain side,  and  beneath  the  pines,  dress  resolves  itself 
into  a  mere  question  of  warmth  and  comfort.  Cut  is 
of  importance  truly,  but  only  insomuch  as  it  allows 
free  play  to  the  limbs;  to  the  arms  in  digging,  and  to 
the  l«gs  in  climbing  the  stiff  side  of  a  canyon.  Home- 
spun, heavy  tanned  duck,  corduroy  or  moleskin,  and 
flannel  underclothing  should  be  the  mainstays  of  a 
miner's  wardrobe.  Rubber  boots  and  slickers  are  also 
necessary  to  his  comfort,  while  for  winter  use  a  heavy 
Mackinaw  overcoat,  or  even  fur,  for  the  extreme  north, 
is  advisable.  When  actually  at  work  the  miner  is 
more  often  in  his  shirt  sleeves  than  not,  and  cold  indeed 
must  the  day  be  if  an  old  woodsman  is  caught  travel- 
ing through  the  forest  with  his  burly  form  encased  in 


CAMP   LIFE.  149 

furs.  For  arctic  conditions  akin  to  those  found  on  the 
upper  Yukon  an  outfit  such  as  the  following  should  be 
chosen : 

2  heavy  knitted  undershirts. 

2  flannel  shirts. 

6  pairs  worsted  socks. 

2  pairs  overstockings. 

i  pair  miner's  boots. 

1  pair  gum  boots. 

2  pairs  moccasins, 
i  suit  homespun. 

I  horsehide  jacket. 
I  pair  moleskin  trousers, 
i  broad-brimmed  felt  hat. 
I  fur  cap. 

1  Mackinaw  overcoat. 

2  pairs  flannel  mitts, 
i  pair  fur  mitts. 

i  muffler. 

1  suit  oil  slickers. 

2  pairs  blankets. 

In  cold  weather  the  feet,  fingers  and  face  require  the 
most  care.  The  first  should  be  stowed  into  two  pairs 
of  wool  socks,  and  a  long  pair  of  knee-high  oversocks 
be  drawn  over  these.  Boots  must  be  replaced  by  moc- 
casins. A  pair  of  thick  worsted  mitts,  and  a  pair 
of  leather  mitts  outside,  keep  the  hands  warm  enough 
even  at  20  degrees  below  zero.  At  50  degrees  below 
put  on  an  extra  pair — or  go  home  until  the  weather 
moderates. 

The  favorite  style  of  architecture  in  the  wilderness 


150  ABC    OF    MINING. 

is  neither  Doric  nor  the  Gothic  nor  yet  the  Renais- 
sance. It  is  called  the  dugout.  The  beauty  of  the 
dugout  is  its  extreme  simplicity.  A  hole  in  the  side 
of  a  dry  bank,  a  few  sods  or  logs  for  roof,  and  there 
you  have  it.  A  veteran  miner  goes  to  earth  as  easily 
as  a  rabbit,  and,  like  bunny,  is  never  at  a  loss  for  an 
habitation. 

Next  to  the  dugout  the  log  cabin  deserves  mention, 
while  the  wattle  and  daub  or  'dobe  certainly  secures 
third  honors.  The  only  drawback  to  the  pre-eminence 
of  the  log  cabin  is  that  to  make  it  you  must  have  logs 
— just  as  the  cook  always  insists  on  pigeons  before  she 
makes  pigeon  pie — and  logs  are  in  some  districts  only 
known  as  museum  specimens.  Now,  the  dugout  or 
the  'dobe  only  require  a  gravel  bank,  or  one  of  those 
deposits  of  argilite  that  the  vulgar  persist  in  calling 
clay;  were  it  not  for  this  fatal  ease  of  getting,  every 
miner  and  prospector  would  doubtless  prefer  living  in 
a  snug  log  hut,  there  to  await  in  peace,  comfort,  and 
dignity  the  arrival  of  the  representative  of  the  "English 
syndicate"  to  whom  he  is  destined  to  sell  his  claim. 

Napoleon  found,  after  fighting  his  way  across  Eu- 
rope and  back  again,  that  his  troops  were  more  healthy 
bivouacking  in  the  open  than  sheltered  in  tents.  In 
truth,  the  tent  is  a  very  uncomfortable  and  unhealthy 
make-shift;  cold,  hot,  and  damp,  by  turns,  and  often 
badly  ventilated.  A  simple  lean-to  shelter,  and  a  roar- 
ing fire  are  infinitely  preferable  where  wood  is  abun- 
dant. But  it  takes  a  lot  of  wood  to  keep  a  bivouac 
warm  on  a  winter's  night;  as  much  perhaps  as  would 
feed  a  fair-sized  family  furnace  for  a  month. 


CAMP   LIFE.  151 

The  trappers'  fire  is  a  most  regal  blaze.  Two  back 
logs;  a  pair  of  "hand  junks"  and  a  "forestick"  are  the 
foundation  upon  which  the  structure  is  reared,  but  the 
edifice  itself  often  consumes  a  tall,  full-limbed  rock 
maple,  or  a  stately  birch  between  the  setting  of  the 
sun  and  the  rising  of  the  same.  There  are  three  ways 
of  making  a  fire;  the  first  is  suited  for  a  "wooden" 
country;  the  second  is  used  by  "Lo,"  and  other  prairie 
travelers,  where  fuel  is  scarce. 

If  overtaken  by  storm  in  any  wild  northern  region, 
do  as  the  animals  and  Indians  do  under  like  circum- 
stances :  seek  the  nearest  shelter  and  lie  close  until  the 
weather  has  moderated.  The  secret  is  to  conserve 
your  energy,  not  to  fritter  it  away  fighting  a  power 
against  which  you  may  make  no  real  headway.  A 
shallow,  brush-lined  gully;  the  lea  of  a  baqk,  or  small 
clump  of  trees;  these  and  other  seemingly  slight  pro- 
tections sometimes  mean  life  instead  of  death.  The 
experienced  woodsman  never  leaves  camp  without 
matches  in  his  pocket;  and  in  winter  he  carries  a  few 
pieces  of  dry  birch  bark  in  the  bosom  of  his  hunting 
shirt,  as  he  knows  how  vitally  necessary  it  is  on  occa- 
sions to  be  able  to  kindle  a  blaze  at  very  short  notice. 

A  tent  should  never  be  pitched  loosely,  as  no  matter 
how  fine  the  evening  the  weather  ere  morning  may  be 
tempestuous  in  the  extreme,  and  the  unpleasantness  of 
having  a  tent  come  down  about  one's  ears  in  the  dark 
must  be  experienced  to  be  realized.  Also,  never  pitch 
a  tent  with  the  doorway  toward  the  northwest  in  win- 
ter, because  that  is  the  quarter  from  which  comes  the 
cold. 


l$2  ABC    OF    MINING. 

In  summer,  from  June  until  mid-August,  the  mos- 
quito, the  black  fly  and  the  midge  or  sand  fly,  make  life 
a  burden  in  the  north.  The  best  remedy  for  the  mos- 
quito and  black  fly  is  a  mixture  of  tar  and  olive  oil, 
of  the  consistency  of  cream,  rubbed  on  all  exposed 
parts  of  the  person.  A  dark  green  veil  will  also  keep 
the  insect  pests  out  of  the  eyes,  mouth  and  ears,  and 
in  \\inter  is  better  than  snow  goggles  to  avert  blind- 
ness. But,  unfortunately,  it  interferes  with  the  en- 
joyment of  the  pipe,  and  hence  is  not  in  much  favor 
with  woodsmen. 

To  make  good  bread  it  is  not  necessary  to  take 
either  yeast  cakes  or  mixing  pan  into  the  wilderness 
An  old  hand  thinks  himself  rich  with  a  few  pounds  of 
flour  in  his  sack,  and  soon  has  a  batch  of  bread  baking 
that  would  turn  many  a  housewife  green  with  envy. 
He  proceeds  in  this  fashion:  A  visit  to  the  nearest 
hardwood  ridge  shows  him  a  green  parasitic  lichen 
growing  on  the  bark  of  the  maples  (lungwort).  Some 
of  this  he  gathers,  and  steeps  it  over  night  in  \varm 
water  near  the  embers.  In  the  morning  he  mixes  his 
flour  into  a  paste  with  this  decoction,  using  the  bag  as 
a  pan.  The  dough  is  next  covered  with  a  cloth  and 
set  in  a  warm  corner  to  rise;  a  few  hours  later  it  is 
re-kneaded  and  baked.  The  result  should  be  delicious 
bread.  Some  of  the  leaven,  or  raised  dough,  may  be 
kept,  and  will  suffice  for  the  next  batch  of  bread,  and 
so  on  ad  infinitum. 

Making  bed  takes  longer  in  camp  than  in  the  city, 
but  the  result  is  just  as  satisfactory.  Nothing  more 
comforting  than  a  couch  of  fir  boughs  has  been  de- 


CAMP   LIFE.  153 

vised  by  man.  Choosing  a  level  spot  the  woodsman 
cuts  several  armfuls  of  the  feathery  tips  of  the  fir  bal- 
sam. These  he  places  in  layers  like  shingles  on  a  roof, 
beginning  at  the  foot  and  laying  the  butt  of  each  bough 
toward  the  head.  If  sufficiently  deep,  say  a  couple  of 
feet  or  so,  such  a  bed  will  be  soft  and  elastic  for  a  night 
or  two,  when  it  will  require  re-laying.  Fragrant  it  al- 
ways is,  with  the  delicious  aroma  of  the  fir  balsam. 

The  white  man  stretches  himself  instinctively  feet 
to  the  fire;  the  Indian  just  as  instinctively  reclines  with 
his  side  to  it — and  his  way  is  the  most  philosophical. 

Strange  as  it  may  seem,  the  greatest  danger  the 
wanderer  runs  is  on  his  return  to  civilization.  Land 
surveyors,  engineers,  and  others  whose  work  calls 
them  into  camp  for  months  at  a  stretch,  dread  their  first 
night  in  a  feather  bed.  They  find  by  experience  that 
they  are  lucky  if  they  escape  with  nothing  more  serious 
than  a  heavy  cold.  Hot,  stuffy  air,  and  poor  ventila- 
tion cause  the  trouble.  Leaving  the  window  wide 
open  will  almost  always  prevent  these  evil  conse- 
quences, and  allow  the  constitution  to  become  once 
more  tolerant  of  a  lack  of  oxygen.  In  the  wilderness, 
notwithstanding,  wet,  cold,  and  exposure,  such  ills  as 
consumption,  pneumonia,  bronchitis,  etc.,  are  un- 
heard of. 

Boat  building  and  net  making  are  two  arts  that  the 
prospector  will  do  well  to  master.  A  few  weeks  passed 
in  a  building  yard,  and  a  half  dozen  lessons  from  an 
old  fisherman  will  teach  him  all  that  he  requires  of 
these  simple  but  extremely  useful  accomplishments. 

The  best  food  for  sustaining  life  in  the  north  i§ 


154  ABC   OF   MINING. 

pemmican.  It  was  once  made  out  of  buffalo  meat,  but 
now  the  flesh  of  the  moose,  or  caribou,  or  of  the  deer, 
is  substituted.  The  meat  is  cut  in  thin  flakes  and  air- 
fried  ;  then  a  mixture  is  made  of  one-third  dried  meat, 
one-third  pure  hunch  fat,  and  one-third  service  berries 
(A  canadensis).  These  are  rammed  by  main  force  into 
a  bag  of  green  hide,  and  pounded  until  as  solid  as  a 
rock.  Such  a  solid  mass  of  food  will  keep  for  years 
in  a  cool  climate. 

Perhaps  the  reader  may  be  inclined  to  exclaim: 
"Why  so  much  about  the  North ;  why  not  more  about 
the  East,  South  or  West?"  My  reply  to  such  would 
be:  Because  the  great  finds  of  the  future  will  surely 
be  made  in  the  North.  Dr.  G.  W.  Dawson,  the  best 
authority  on  the  subject,  has  said  there  are  1,000,000 
square  miles  of  virgin  territory  in  Canada  to-day,  and 
no  doubt  a  very  large  proportion  of  it  contains  mineral 
deposits.  This  1,000,000  square  miles  he  divides  into 
sixteen  separate  areas,  some  half  as  large  as  Ireland, 
others  half  that  of  Europe,  and  in  none  of  them  has 
the  footfall  of  a  white  man  yet  been  echoed. 


SURVEYING.  155 


CHAPTER  VII. 
SURVEYING. 

A  man,  to  make  a  success  of  prospecting,  must  have 
what  is  known  as  "a  good  eye  for  a  country."  Given 
that  faculty  he  will  readily  pick  up  the  little  knowledge 
of  surveying  that  is  sometimes  almost  indispensable. 
A  tape  measure,  and  a  prismatic  or  surveying  compass, 
are  all  that  he  is  likely  to  require  in  laying  off  to  his 
own  satisfaction  the  extent  of  his  claim,  or  any  similar 
simple  operation.  The  surveying  compass  has  two 
fixed  sights,  and  a  Jacob  staff  mounting,  into  which 
a  wooden  support  is  inserted.  The  north  end  of  the 
compass  is  always  pointed  ahead,  while  the  needle, 
which  of  course  indicates  the  magnetic  north,  gives 
the  bearing  of  the  line  run  toward  that  north.  Now, 
magnetic  north  is  not  by  any  means  the  same  thing  as 
true  north,  in  fact  in  very  few  localities  on  the  earth's 
surface  are  they  the  same,  and  then  never  for  long. 
In  the  extreme  east  of  the  United  States  the  needle 
points  some  twenty  degrees  to  the  west  of  true  north, 
and  in  Alaska  it  points  thirty-five  degrees  to  the  east- 
ward of  it.  There  is  therefore  one  meridian  some- 
where in  the  central  valley  where  the  true  north  cor- 
responds with  the  magnetic  north,  but  as  the  magnetic 
pole  is  always  shifting  this  never  remains  true  of  the 
same  meridian  for  long. 

When  there  is  no  local  magnetism  from  iron  ores, 


156  ABC    OF    MINING. 

or  rocks  containing  magnetite,  the  needle  is  fairly  reli- 
able, though  never  perfectly  accurate,  but  when  such 
attraction  exists  the  compass  is  unsatisfactory.  Such 
areas  of  attraction,  however,  are  usually  limited,  and 
by  squinting  back,  taking  what  is  known  as  a  "back 
sight,"  a  local  attraction  may  be  detected,  and  in  that 


SURVEYING  COMPASS. 

case  ranging  by  rods  must  be  resorted  to  until  the 
compass  needle  once  more  seeks  its  true  position.  To 
range  by  rods  the  course  of  the  line  having  been  deter- 
mined by  retracing  the  route  followed  to  the  last  reli- 
able mark,  a  stake  is  driven  in  at  that  point,  and  the 
surveyor  standing  some  little  distance  behind  it  on 


SURVEYING.  157 

the  correct  line  directs  an  assistant  to  place  another 
rod  in  such  a  position  that  the  first  hides  it  from  view. 
It  will  then  be  on  a  prolongation  of  the  line,  and  this 
operation  being  continued  the  surveyor  will,  in  due 
time,  find  himself  beyond  the  reach  of  the  local  attrac- 
tion that  deflected  his  needle  and  can  resume  compass 
work. 

A  chain  is  66  feet  long.  Oftentimes  in  mountain- 
ous or  brush-covered  countries  a  half  chain  of  33  feet, 
made  of  light  wire  links,  is  preferred.  Two  men  do 
the  chaining,  which  could  of  course  be  done  by  means 
of  an  ordinary  tape  measure  in  an  emergency,  the  lead- 
er carrying  ten  pins  of  iron  or  wood,  and  the  rear  man 
taking  one  up  as  each  chain  is  measured  off.  When 
all  are  used,  ten  chains  ($  mile)  have  been  covered. 
The  men  exchange  pins  and  the  tally  man,  usually  the 
hind  chainman,  calls  out  "Tally  one,"  and  cuts  a  notch 
in  a  stick.  Careful  chaining  is  the  essence  of  good 
surveying.  The  chain  must  always  be  kept  horizontal, 
or  else  an  allowance  made  for  the  inclination  at  which 
it  was  held  when  the  measurement  was  taken,  other- 
wise the  results  will  be  misleading,  for  all  surveyors' 
measurements  of  areas  are  theoretically  on  a  flat  sur- 
face. 

To  ascertain  the  height  of  a  tree,  tower,  etc.,  fold  a 
square  of  paper  across,  and  glancing  along  the  hypoth- 
enuse  (longest  side)  of  the  right  angle  so  found,  as- 
certain at  what  point  your  line  of  sight  just  catches 
the  top  of  the  object.  Then  its  height  is  the  same  dis- 
tance as  the  distance  from  where  you  stand  to  its  foot, 
or  the  length  of  a  plumb  line  falling  from  its  summit, 


158 


ABC    OF    MINING. 


together  with  the  height  of  your  eye  above  the  ground, 
added. 

Another  method  is  to  measure  the  sh'adow  of  the 
object  on  a  level  surface,  next  measure  your  own. 
Then 

As  your  shadow  is  to 
your  height  so  is  the 
shadow  of  the  object  to 
its  height. 

The  area  of  a  square       / 

is  equal  to  the  square      I 
of  one  of  its  sides. 

The  area  of  a  triangle  is  equal  to  the  base  multiplied 
by  half  the  height. 

The  areas  of  figures  containing  more  than  three 
sides  may  always  be  found  by  resolving  such  figures 
into  a  series  of  right  angled  triangles. 

Very  frequently  the  surveyor  is  called  upon  to 
measure  an  inaccessible  line.  There  are  many  ways 
of  solving  such  a  problem,  but  one  of  the  simplest  is 
as  follows: 


SURVEYING.  159 

Supposing  the  required  distance  is  that  from  bank 
to  bank  of  a  river  (Y-X).  Then  lay  off  the  bas.e  line 
Y-M,  driving  stakes  at  each  end;  make  M-P  at  right 
angles  to  Y-M.  Sight  from  P  to  X,  and  drive  in  a 
stake  at  Z.  Then: 


ZM  :MP::ZY:YX. 

While  these  simple  surveying  problems  are  easily 
solved,  the  prospector  should  never  forget  that  mine 
surveying  requires  skill,  experience  and  accuracy.  Efe 
will  do  well  always  to  call  in  the  service  of  a  mining 
engineer  should  his  "prospect"  ever  become  a  full- 
fledged  mine,  as  little  errors,  of  direction  are  particu- 
larly costly  mistakes  when  they  occur  underground. 

Should  you  wish  to  lay  off  a  certain  acreage  as  a 
square,  proceed  as  follows: 

As  there  are  ten  square  chains  to  one  acre,  multiply 
the  content  in  acres  by  10  to  reduce  to  square  chains. 
Then  find  the  square  root  of  this  number  of  square 
chains,  and  that  will  be  the  length  of  a  side  of  the 
square  required.  For  instance: 

To  lay  off  25  acres  as  a  square: 

25  times  10  equals  250  square  chains. 

Whose  square  root  is  15.81. 

Ans.    The  plot  must  be  15  chains  81  links  square. 

Seventy  average  paces  is  almost  exactly  equal  to 
the  side  of  a  square  acre. 

If  you  know  the  content  and  length  of  one  of  the 


160  ABC   OF   MINING. 

sides  of  a  rectangular  figure  it  is  easy  to  lay  it  off. 
Thus: 

Given  a  claim  10  chains  long,  how  wide  must  it  be 
to  cover  5  acres? 

5  times  10  equals  50  square  chains. 

10  divided  by  50  equals  5. 

Ans.    5  chains  wide. 


FLOATING  A  COMPANY.  161 


CHAPTER   VIII. 

FLOATING  A  COMPANY. 

Should  the  prospector  discover  mineral  that  in- 
creases in  amount  as  the  mine  is  opened,  and  shows 
that  it  is  likely  to  prove  a  profitable  deposit,  he  will 
have  little  difficulty  in  selling  out  to  some  wealthy 
syndicate.  But  if  his  mine  is  likely  to  become  a  big 
producer  he  should  try  rather  to  organize  a  company, 
of  which  he  should  be  a  shareholder — the  controlling 
one  if  possible — as  then  the  output  of  the  mine  will 
probably  make  him  a  rich  man.  It  is  rare  that  a  pros- 
pector selling  outright  obtains  anything  but  a  fraction 
of  the  value  of  a  good  mine.  Nor  is  it  reasonable  to 
suppose  he  should.  When  'he  sells,  the  profits  of  the 
buyers  are  all  in  the  future,  and  may  never  materialize. 
They  take  all  risk,  and  consequently  insist  upon  a 
bargain. 

The  more  money  a  prospector  can  invest  in  the 
development  of  a  good  mine  the  better  price  he  is 
likely  to  get  when  he  sells.  Business  men  dearly  like 
to  see  great  masses  of  ore  in  the  shafts  and  cuts,  and 
are  always  more  willing  to  pay  a  handsome  price  when 
they  know  something  distinctly  promising  about  the 
purchase. 

Let  the  prospector,  therefore,  lay  open  his  prospect 
as  thoroughly  as  he  can  with  the  means  at  his  dis- 
posal, and  if  he  has  faith — as  he  should  have — in  the 
11 


162  ABC   OF   MINING. 

mine  he  is  selling,  let  him  take  a  good  big  block  of 
stock  in  part  payment. 

He  must  see  to  it,  too,  that  sufficient  working  capi- 
tal is  provided,  as  there  are  very  few  mines  that  pay 
expenses  from  the  start.  Sometimes,  when  the  share- 
holders are  very  timid,  and  but  little  money  has  been 
paid  into  the  treasury  in  the  first  instance,  they  become 
restive  after  a  call  or  two  and  refuse  to  honor  further 
demands.  This  has  been  the  ruin  of  many  a  promising 
venture. 

Supposing,  however,  that  this  mistake  has  been 
avoided,  and  that  sufficient  funds  are  in  the  treasury 
to  meet  all  likely,  legitimate  drains  upon  it,  the  ques- 
tion of  officers  remains  a  weighty  one.  The  board  of 
directors  should  be  level-headed,  shrewd  men,  with 
common-sense,  business  ideas;  the  secretary  should 
understand  his  work;  and  the  mining  engineer  placed 
in  charge  of  the  mine  should  be  one  whose  professional 
knowledge  is  equal  to  the  demands  of  the  position. 
The  secretary  must  have  such  a  knowledge  of  the 
proper  price'  of  labor,  and  material,  as  to  detect  any 
extravagance  on  the  part  of  the  manager. 

At  least  one  member  of  the  board  of  directors  should 
understand  mining.  Good  salaries  paid  to  the  mining 
engineer  or  manager,  and  to  the  secretary,  will  be 
money  well  spent,  provided  they  are  competent. 
Cheap  men  have  no  business  in  such  responsible  posi- 
tions, where  the  handling  and  wise  expenditure  of  large 
sums  of  money  necessitate  brains  and  special  training. 

As  to  the  mine  manager,  he  should  be  a  miner,  sur- 
veyor, metallurgist,  assayer,  bookkeeper  and  half- 


FLOATING  A  COMPANY.  163 

dozen  other  things  rolled  into  one,  and  that  one  an 
honest  man.  Very  low  grade  ore  would  probably  pay 
in  the  hands  of  such  a  paragon  of  perfection — but  he 
must  be  sought  for  long  and  diligently,  and  even  then 
he  may  not  be  found. 

New  processes  are  to  be  shunned  until  they  have 
proved  their  worth  and  ceased  to  be  new.  No  sooner 
is  a  mine  floated  than  all  sorts  of  knaves  and  fools  ap- 
pear on  the  scene,  with  new  and  wonderful  appliances 
for  saving  99.9  per  cent  of  all  the  value  in  the  ore.  Be 
rude  to  them.  Drive  them  away  with  sticks  and  stones 
if  necessary,  but  as  you  value  your  salvation  do  not 
hearken  to  them.  Let  some  one  else  do  the  experi- 
menting; when  you  know  a  process  is  good,  the  time 
will  have  come  to  spend  money  on  it.  There  are  at 
the  present  moment  thousands  of  tons  of  costly  ma- 
chinery rusting  in  lonely  Rocky  Mountain  canyons 
that  were  in  their  day  "novelties,"  warranted  to  save 
all  the  values  in  the  ore,  while  the  unfortunate  share- 
holders, whose  misspent  money  freighted  these  things 
to  their  final  resting  place,  are  now,  perchance,  "touch- 
ing" the  belated  Chicago  or  New  York  pedestrians  for 
a  nickel. 

The  only  real  guide  to  the  economic  value  of  an 
ore  is  the  treatment  of  a  large  bulk  of  it  in  the  mill. 

Plenty  of  ore  should  be  kept  blocked  out  ahead  of 
the  workings.  The  more  ore  in  sight  the  better  for 
the  future  of  the  mine. 

Lastly,  remember  that  thieving  sometimes  takes 
place  on  rather  a  large  scale,  and  be  on  the  watch  to 
detect  it. 


164  ABC   OF   MINING. 

But  there  is  a  bright  side  to  mining  as  well  as  a 
dark,  and  those  fortunate  men  who  paid  3,  5  or  8  cents 
for  the  stock  of  a  mine  that  now  sells  for  $7  can  see 
it  quite  plainly;  and  there  are  many  such.  Mining  is 
not  a  gamble  as  some  would  have  the  world  believe, 
but  a  legitimate  occupation,  demanding  great  nerve 
and  skill,  and  sometimes  great  patience,  but  not  in- 
frequently rewarding  the  possessors  of  these  admirable 
attributes  by  wealth  almost  inexhaustible. 


MEDICAL  HINTS.  165 


CHAPTER  IX. 

MEDICAL  HINTS. 

Miners  as  a  rule  are  a  healthy,  hardy  lot  of  men, 
but  nevertheless  they  are  occasionally  taken  ill,  and 
there  is  very  seldom  a  doctor  near  at  hand.  More- 
over, by  the  very  nature  of  their  work  they  are  particu- 
larly liable  to  accidents. 

The  so-called  miner's  consumption  is  caused  by 
want  of  fresh  air.  The  miner  passes  most  of  his  life 
in  places  where  there  is  a  great  deficiency  of  oxygen. 
Deep  down  in  the  mine  the  air  is  usually  very  bad,  be- 
ing full  of  smoke  and  damp,  and  the  hut  in  which  he 
sleeps  is  too  often  overcrowded,  while  the  places  in 
which  he  seeks  his  amusement,  should  he  live  in  a  min- 
ing camp,  are  usually  little  better.  The  remedy  for 
this  state  of  affairs  is  to  get  all  the  fresh  air  possible, 
then  consumption  is  not  to  be  feared. 

Should  poison  have  been  swallowed,  an  emetic 
ought  to  be  given  as  quickly  as  possible.  Mustard, 
or  salt  and  warm  water,  are  tolerably  efficacious,  but 
a  dose  of  60  grains  of  ipecac  is  more  effectual.  While 
the  emetic  is  acting,  the  patient  should  drink  freely  of 
warm  water  or  warm  milk. 

In  case  of  apparent  drowning  the  body  should  be 
stripped  down  to  the  waist,  rapidly  dried,  placed  on  a 
flat  surface  with  the  head  and  shoulders  raised  a  little, 
and  hot  bricks  applied  to  the  feet.  Breathing  should 


166  ABC   OF   MINING. 

be  imitated  by  raising  the  arms  above  the  head  and 
turning  the  body  on  its  side;  turn  the  body  back  on 
the  face  and  press  the  arms  down  to  the  side.  Do  this 
about  sixteen  times  a  minute,  and  keep  it  up  half  an 
hour  if  necessary. 

In  case  of  a  wound  which  bleeds  freely,  a  distinction 
must  be  made  between  blood  issuing  from  a  vein  and 
blood  issuing  from  an  artery.  In  the  first  instance, 
it  will  be  nearly  black,  or  at  least  very  dark;  in  the 
second,  it  will  be  bright  red  and  spurt  forth.  When 
from  a  vein,  bleeding  must  be  controlled  by  pressure 
below  the  wound,  that  is,  farther  away  from  the  heart, 
while  in  the  case  of  an  artery,  which  is  always  more 
dangerous,  immediate  pressure  must  be  made  above 
the  wound  on  the  line  of  the  artery  between  the  wound 
and  the  heart.  A  pebble  rolled  up  in  a  handkerchief 
and  tied  around  the  limb,  with  the  stone  directly  above 
the  artery,  and  tightened  by  twisting  a  stick  in  it,  is 
a  good  rough-and-ready  means  to  stop  bleeding. 
Sometimes  a  pad  should  be  placed  between  the  hand- 
kerchief and  the  artery. 

Anything  that  excludes  the  air,  such  as  wheat  flour, 
or  olive  oil,  or  boiled  linseed,  or  grated  raw  potato,  is 
good  to  spread  over  a  burn.  If  any  considerable  sur- 
face is  burned  the  patient  is  in  great  danger,  but  small 
burns  are  rarely  fatal,  although  they  may  be  very  pain-' 
ful.  The  best  application  of  all  is  linseed  oil  and  lime 
water. 

Scurvy  is  a  disease  that  is  very  much  to  be  dreaded 
whenever  fresh  meat  and  vegetables  are  scarce.  It  is 
now  thought  to  be  a  condition  of  acid-poisoning,  and 


MEDICAL  HINTS.  167 

the  remedy  is  alkaline  salts,  such  as  carbonate  of  soda 
or  carbonate  of  potash.  Lime  juice  is  also  an  anti- 
scorbutic. In  cold  weather  a  diet  of  almost  exclusively 
fresh  fat  meat  will  keep  off  scurvy. 

Pneumonia  is  usually  most  fatal  in  crowded  camps, 
where  the  men  do  not  get  a  sufficient  amount  of  pure, 
fresh  air. 


168  ABC    01-    MIXING. 


CHAPTER   X. 

DYNAMITE. 
» 

Dynamite  should  be  stored  in  a  magazine  which 
must  be  dry,  cool,  and  well  ventilated.  Bricks  are  best, 
but  when  built  of  wood,  the  frame  should  be  covered 
inside  and  out  with  boards  allowing  the  air  to  have 
free  circulation  between  the  walls,  so  that  the  inner 
wall  may  not  be  heated  by  the  sun. 

Do  not  store  your  caps  with  your  dynamite. 

If  powder  was  well  made,  it  is  as  good  a  dozen  years 
afterwards  as  it  was  on  the  day  it  came  from  the 
mill. 

Most  accidents  occur  in  thawing  dynamite.  Dyna- 
mite freezes  between  40  and  45  degrees  Far.,  that  is, 
10  degrees  above  the  freezing  point  of  water,  and  al- 
though it  does  not  explode,  if  heated  slowly,  until  320 
degrees  Far.  is  reached,  yet  the  quick  application  of 
dry  heat  may  explode  it  at  120  degrees  Far.  This 
makes  it  so  dangerous,  for  a  stick  of  powder  hot 
enough  to  explode  under  certain  conditions  may  be 
held  in  the  hand  with  little  inconvenience.  Powder 
should  be  thawed  by  placing  it  in  a  water-tight  vessel 
and  the  vessel  set  in  'hot  water.  It  should  never  be 
placed  on  or  under  a  stove,  or  in  an  oven,  or  on  a  boiler 
wall  to  thaw  out,  as  is  so  often  done  by  the  unthinking. 
Frozen  dynamite  is  especially  liable  to  explode  from 
heat  quickly  applied.  Nevertheless,  reckless  men  will 


DYNAMITE.  169 

continue  to  blow  themselves  to  pieces  by  foolhardy 
carelessness. 

Frozen  powder  is  unfit  for  use.  It  will  burn  or 
smoulder,  and  some  of  it  may  be  left  in  the  drill  hole 
to  explode  when  it  is  not  wanted  to. 


170  ABC    OF    MINING. 


CHAPTER    XI. 
ATOMIC  WEIGHTS. 

The  atomic  weight  of  a  mineral  is  the  proportion 
in  which  its  elements  are  united,  i.  e.,  they  represent 
the  weights  of  the  different  atoms  in  the  minerals. 
Hydrogen,  being  lightest,  is  made  the  unit. 

Supposing  it  becomes  desirable  to  find  the  propor- 
tional weights  of  the  elements  of  any  substance  with 
a  known  chemical  formula.  Multiply  the  atomic 
weight  of  each  element  by  the  number  of  atoms  of  such 
element,  and  add  these  products  together;  this  will 
give  the  weight  of  all.  The  proportion  of  each  is  ar- 
rived at  by  a  simple  calculation. 

For  instance:  How  much  metallic  silver  is  there 
in  100  pounds  of  Argentite,  or  silver  glance,  whose 
composition  is  Ag2S? 

Then 

Ag  equals  108  times  2,  —  216. 
S  equals  32  times  I,  —  32. 

So  that  in  every  248  pounds  of  the  glance  there  are 
216  pounds  of  metallic  silver,  and  by  proportion  we 
find  its  percentage  is  87.1. 

The  following  tables  give  the  symbols,  atomic 
weights  and  specific  gravities  of  certain  abundant  ele- 
ments. Rare  elements  are  omitted: 


ATOMIC  WEIGHTS.  171 

Symbol.  At.Wt.  Sp.  Gr. 

Aluminum   Al  27 . 5  2 . 56 

Antimony     Sb  122.0  6.70 

Arsenic    As  75  5.70 

Barium     Ba  137  4 .00 

Bismuth Bi  210  9.7 

Calcium   Ca  40  i .  58 

Carbon  C             12  3.50 

Chromium Cr  52.5  6.81 

Cobalt    Co  58.8  7.70 

Copper     Cu  63.5  8.96 

Gold  (Auruni) Au  196.77  19.30 

Hydrogen    H              i.o.  0.069 

Iodine    I  127.0  4.94 

Iron  (Ferrum) Fe  56 . o  7-79 

Lead  (Plumbum) Pb  207.0  n .44 

Manganese     Mn  55  .o  8.1 

Mercury  (Hydrargyrum)  .  . .  .Hg  200  J3'59 

Nickel    '. Ni  58.8  8.60 

Nitrogen   N             14.0  0.972 

Oxygen O             16.0  1.105 

Phosphorus P  31.0  1.83 

Platinum    Pt  197-4  21.53 

Potassium  ({Calium) K  39.0  0.865 

Selenium   Se  79-5  4-78 

Silicon   Si  28.0  2.49 

Silver  (Argentum) Ag  108.0  10.05 

Sodium  (Natrium) Na  23.0  0.972 

Sulphur    S  32.0  2.05 

Tellurium     Te  129.0  6.02 

Tin  (Stannum) Sn  118.0  7.28 

Zinc    Zn  65.0  7.14 


172  ABC   OF    MINING. 

CHAPTER    XII. 
ODDS  AND  ENDS. 

MINER'S  INCH. 

A  miner's  inch  of  water  varies  in  different  States, 
and  is,  therefore,  not  a  fixed  quantity.  In  some  States 
it  means  the  quantity  of  water  that  will  flow  through 
an  orifice  one  inch  square  on  the  bottom  or  side  of  a 
box  under  a  pressure  of  four  inches.  Under  these 
conditions  a  miner's  inch  will  discharge  2259  cubic 
feet,  or  17,648  gallons  every  twenty-four  hours,  which 
is  at  the  rate  of  12  gallons  a  minute.  Fifty  of  these 
miner's  inches  are  equal  to  a  cubic  foot  of  water  dis- 
charged every  second.  One  cubic  foot  of  water  a 
second  would  be  sufficient  to  supply  the  wants  of 
seven  thousand  city  dwellers. 

In  calculating  the  amount  of  water  required  by 
a  stamp  mill  it  is  usual  to  allow  72  galtons  for  every 
stamp,  1 20  gallons  for  every  pan,  75  gallons  for  every 
settler,  120  gallons  for  every  Fruevanner,  30  gallons 
for  a  concentrator,  350  gallons  for  a  jig,  and  7i  gal- 
lons for  every  horse-power  of  a  boiler  each  hour.  If 
the  water  after  passing  through  the  mill  is  impounded 
and  used  over  again,  the  loss  will  be  about  25  per 
cent 

LUMBER  IN  A  LOG. 

To  Find:  Multiply  the  diameter  in  inches  at  the 
small  end  by  one-half  the  number  of  inches,  and  again 


OUDS  AND  ENDS.  1/3 

multiply  this  product  by  the  length  of  the  log  in  feet; 
this  product  divided  by  12  will  give  the  number  of 
feet  of  one-inch  boards  the  log  will  make. 

HORSE-POWER  OF  BOILERS. 

For  horizontal,  tubular  an'd  flue  boilers,  divide  the 
number  of  feet  of  heating  surface  by  15;  this  will  give 
the  horse-power.  A  cord  of  pine  wood  weighing  2,000 
pounds  is  about  equal  to  1,000  pounds  of  soft  coal  for 
steam  purposes.  Each  foot  of  grate  should  burn  20 
pounds  of  soft  coal,  or  40  of  wood,  per  hour,  with  a 
natural  draught. 

HORSE-POWER  OF  AN  ENGINE. 

Multiply  the  area  of  the  cylinder  in  square  inches 
by  the  average  effective  pressure  in  pounds  to  the 
square  inch,  deducting  three  pounds  per  square  inch 
for  friction.  Multiply  this  remainder  by  the  speed  of 
the  piston  in  feet  per  minute,  and  divide  by  33,000. 
The  quotient  will  be  the  true  horse-power. 

HORSE-POWER  OF  PELTON  WHEEL. 

The  Pelton  wheel  is  in  high  favor  with  California 
miners.  When  the  head  of  water  is  known  in  feet,  mul- 
tiply by  0.0024147  and  the  product  is  the  horse-power 
that  one  miner's  inch  of  water  will  give. 

ASSAYING. 

The  muffle  furnaces  of  the  Morgan  Crucible  Com- 
pany of  Battersea  are  favorably  known.  The  most 


174  ABC   OF   MINING. 

useful  size  is  that  taking  a  "D"  Muffle,  8£  inches  by 
5  inches  by  3^  inches. 

A  CHEAP  "TESTING"  OUTFIT. 

Sometimes  the  pioneer  is  forced  to  attempt  a  good 
many  investigations  with  very  simple  apparatus. 
Should  he  possess  the  following,  he  can  achieve  much : 
A  spirit  lamp,  candle,  blow-pipe,  magnet,  a  bottle  of 
hydrochloric  acid,  quart  glass  jar,  three  test  tubes 
with  corks,  two  feet  of  glass  tubing  (hard  glass),  cop- 
per wire,  two  square  inches  of  tin  plate,  forceps  and 
test  paper.  Such  an  outfit  could  certainly  be  bought 
for  $i. 

WEIGHT  OF  EARTH,  SAND,  GRAVEL,  ETC. 

A  ton  of  shingle  averages  23  cubic  feet. 

A  ton  of  pit  sand  averages  22  cubic  feet. 

A  ton  of  earth  averages  21  cubic  feet. 

A  ton  of  river  sand  averages  19  cubic  feet. 

A  ton  of  coarse  gravel  averages  19  cubic  feet. 

A  ton  of  clay  averages  18  cubic  feet. 

A  ton  of  marl  averages  18  cubic  feet. 

A  ton  of  chalk  averages  14  cubic  feet. 

WEIGHTS  OF  ORES  AND  ROCKS. 

Quartz,  162  pounds  a  cubic  foot;  silver  glance,  455 
pounds;  ruby  silver,  362;  brittle  silver,  386;  horn 
silver,  345;  antimony  glance,  287 ;  cinnabar,  549 ;  cop- 
per pyrites,  262;  gray  copper,  280;  galena,  461;  zinc 
blende,  249;  iron  pyrites,  312;  limestone,  174;  clay, 
162. 


ODDS  AND  ENDS.  175 

CALIFORNIA  PUMP. 

A  very  useful  pump,  in  regions  where  transporta- 
tion is  a  problem,  is  the  California  pump.  It  is  a 
rough  chain-pump.  A  box  10  inches  by  3  inches,  in- 
side measurement,  and  10  feet  to  30  feet  in  length, 
according  to  requirements,  forms  a  tube  reaching  from 
the  water  to  be  removed  to  the  level  at  which  it  is  to 
be  discharged.  In  this  an  endless  band  of  stout  canvas 
or  leather  works,  passing  under  a  roller  at  the  lower 
end,  which  is  immersed  in  the  water.  At  the  higher 
end  the  belt  passes  around  a  drum  worked  by  water, 
horse,  or  manual  power.  On  the  belt  are  wooden  or 
metal  projections  that  fit  the  box,  forcing  the  water 
upward  as  the  drum  revolves. 

HYDRAULIC  DATA. 

The  prospector,  and  more  especially  the  miner,  will 
do  well  to  commit  the  following  figures  to  memory: 

An  Imperial  gallon  of  water  weighs  10  pounds. 
Gallons  multiplied  by  .  1606  equals  cubic  feet. 
Cubic  feet  multiplied  by  6.288  equals  gallons. 
Gallons  multiplied  by  277.46  equals  cubic  inches. 
Cubic  indhes  multiplied  by  0.003604  equals  gallons. 
Cubic  feet  multiplied  by  62.8  equals  pounds. 
Pounds  multiplied  by  .0166  equals  cubic  feet. 
Gallons  multiplied  by  0.004464  equals  tons. 
Tons  multiplied  by  224  equals  gallons. 
Tons  multiplied  by  35.97  equals  cubic  feet. 

A  head  of  10  feet  gives  a  pressure  of  about  4  1-3 
pounds  to  the  square  inch.  Let  H  represent  the  head 


176  ABC   OF   MINING. 

of  water  in  feet,  and  P  the  pressure  to  the  square  inch. 
Then: 

H  equals  P  times  2.311. 

P  equals  H  times  .4326. 

A  FIRE  LUTE. 

To  make  a  fire-proof  joint  between  the  lid  and  body 
of  a  retort,  or  crucible,  use  the  following  as  a  lute: 

Quartz  sand 8  parts. 

Clay  (pure  as  possible) 2  parts. 

Horse  dung I  part. 

Mix  and  temper  like  mortar. 

CONTENTS  OF  A  VEIN. 

To  find  the  number  of  cubic  feet  per  fathom  of 
matter  in  a  vein,  multiply  its  thickness  in  inches  by  3. 
Great  care  is  requisite  in  estimating  the  ore  in  a  vein 
or  the  amount  of  mineral  in  sight.  Very  clever  men 
often  make  grave  mistakes  in  such  calculations. 

A  MAKE-SHIFT  FLUX. 

Rough  smelting  may  be  done  with  powdered  white 
glass,  though  either  borax  or  carbonate  of  soda  is 
better.  As  soon  as  the  gold  is  melted  and  the  flux 
fluid  and  still,  remove  the  bulk  of  the  flux  with  an  iron 
spoon,  and  pour  the  metal  into  a  clay  mould.  Crush 
the  flux  for  gold. 

SAVING  BLAST  SAMPLES. 

Place  a  quantity  of  spruce  boughs  over  a  hole  before 
tiring  the  shot,  and  very  few  stones  will  fly. 


ODDS  AND  ENDS.  177 

A  SIMPLE  RETORT. 

Squeeze  the  quicksilver  amalgam  containing  gold 
through  a  chamois  skin  or  piece  of  cotton  until  it  is 
as  dry  as  you  can  get  it.  Then  take  a  large  potato, 
cut  off  one  end  and  hollow  out  a  piece  of  it  large 
enough  to  receive  the  amalgam.  Heat  a  shovel  or  a 
piece  of  sheet  iron  red  hot,  hold  the  potato  up  and 
press  the  shovel  to  it,  covering  the  amalgam.  As  soon 
as  the  potato  sticks  fast  to  the  shovel,  turn  it  over  so 
that  the  potato  is  on  the  top  and  place  it  over  the  fire 
and  keep  it  red  hot  until  the  retorting  is  finished.  As' 
soon  as  it  cools,  loosen  the  potato  with  a  knife,  and  the 
gold  will  be  underneath  and  the  quicksilver  in  the 
potato.  The  quicksilver  may  be  recovered  by  bruising 
the  potato  to  pulp  in  a  cup  with  water. 

CLEANING  AMALGAMATED  PLATES. 

A  very  simple  plan  for  getting  the  gold  off  an 
amalgamated  copper  plate  is  as  follows:  Take  out  the 
surface  dirt  for  the  depth  of  nine  inches  over  an  area 
a  little  larger  than  the  plate  to  be  scaled;  place  six 
bricks  around  the  excavation  as  supports  for  the  plate. 


Make  a  brick  fire,  and  let  it  burn  down  to  red  hot 
embers.  Lay  the  plate  on  three  iron  bars  resting  on 
the  bricks,  and  cover  the  face  with  strips  of  old  blanket 
soaked  in  a  strong  solution  of  borax.  Keep  the 
12 


178  ABC   OF    MINING. 

blankets  wet  with  the  solution,  and  when  the  amalgam 
is  white,  remove  the  plate  and  scrape. 

CALCULATING  WEIGHT  OF  ORE. 

Measure  the  cubic  contents  of  the  mass;  multiply 
this  by  the  weight  of  one  cubic  foot  of  the  mineral. 

For  small  masses,  where  no  scales  are  at  hand,  fill 
a  bucket  with  water,  and  stand  it  in  an  empty  barrel. 
Fill  the  bucket  brimful;  introduce  the  rock,  or  ore, 
and  measure  the  water  it  displaces.  Find  the  number 
of  cubic  inches  in  the  overflow  by  reference  to  the 
following  table: 

i  gallon  equals  231  cubic  inches, 

i  quart  equals  57.75  cubic  inches. 

fi  pint  equals  28.87  cubic  inches, 

i  gill  equals  7.21  cubic  inches. 

Multiply  the  total  so  found  by  the  specific  gravity 
of  the  ore,  and  the  result  will  be  the  answer  sought. 

Supposing  the  bottom  of  the  bin  to  be  wedge-shaped, 
measure  half  the  height  from  the  bottom  to  the  top 
and  multiply  the  number  of  feet  by  the  width  and 
length,  both  in  feet.  This  will  give  number  of  cubic 
feet  in  the  bin.  Multiply  the  number  of  cubic  feet  by 
the  weight  of  one  cubic  foot  of  the  ore,  and  the  result 
will  show  the  number  of  pounds  of  ore  the  bin  will 
hold.  Divide  by  2,000  to  reduce  to  tons. 

MINING  REGULATIONS. 

The  mining  regulations  of  every  country  differ,  and 
the  prospector  must  learn  by  heart  the  provisions  of 
the  one  he  works  under.  A  claim  notice  written  with 


ODDS  AND  ENDS.  179 

a  hard  pencil  or  surveyor's  marking  lead  on  a  soft  pine 
board  will  last  for  years. 

WEIGHTS  AND  MEASURES. 

Troy  Weight. 

24  grains I  pennyweight. 

20  pwts i  ounce. 

12  ounces i  pound. 

Long  Measure. 

12  inches    i  foot. 

3  feet    i  yard. 

2  yards i  fathom. 

16^  feet i  rod. 

4  rods  i  chain. 

10  chains    i  furlong. 

8  furlongs    i  mile. 

Square  Measure. 

9  sq.  feet   i  sq.  yard. 

30^  sq.  yds i  sq.  rod. 

40  sq.  rods    i  sq.  rood. 

4  sq.  roods i  sq.  acre. 

640  sq.  acres i  sq.  mile. 

An  acre  is  209  feet  square. 

Land  Measure. 

7 .92  inches I  link. 

25  links    I  rod. 

4  rods i  chain. 

80  chains    i  mile. 

Avoirdupois  Weight. 

16  drams i  ounce. 

16  ounces  i  pound. 

25  pounds i  quarter. 

4  quarters    i  cwt. 

2O  cwt.  (2,000  pounds) i  ton. 


l8o  ABC   OF   MINING. 

Apothecary's  Weight. 

20  grains i  scruple. 

3  scruples i  dram. 

8  drams i  ounce. 

12  ounces   I  pound. 

GLOSSARY. 

Adamantine — Having  diamond  luster. 

Adit — A  horizontal  tunnel  from  the  surface  drain- 
ing a  mine. 

Alluvium — Deposit  by  streams. 

Amalgamation — Combining  mercury  with  another 
metal. 

Analysis — A  chemical  search  whereby  the  nature 
(qualitative)  and  amount  (quantitative)  of  the  compo- 
nents of  a  substance  are  found  out. 

Aqua  regia — A  mixture  of  3  parts  hydrochloric  acid 
with  i  part  strong  nitric  acid. 

Arenaceous — Sandy. 

Argentiferous — Silver-bearing. 

Argillaceous — Clay-bearing. 

Arrastra — A  rotary  and  primitive  mill. 

Assay — A  test. 

Assay-ton — 29.166  2-3  grammes. 

Auriferous — Gold-bearing. 

Bar — Obstruction  in  the  bed  of  a  river. 

Bar-diggings — Claims  in  the  shallows  of  streams. 

Base  Metals — Those  not  classed  as  precious. 

Batea — Mexican  gold-washing  dish. 

Battery — A  set  of  stamps  for  crushing. 

Bed — A  seam  or  deposit. 

Bed-rock — Solid  stratum  below  porous  material. 


GLOSSARY.  181 

Bench — Old  river  bed;  also  called  a  terrace. 

Booming — The  sudden  discharge  of  accumulated 
water. 

Bort — Black  diamond. 

Calcite — Carbonate  of  lime. 

Canon — Pronounced  canyon;   a  gorge. 

Carat — About  4  grains  Troy. 

Cement — Compacted  gravel. 

Color — A  speck  of  gold. 

Country  Rock — The  rock  enclosing  a  vein. 

Cradle — A  mining  apparatus;   also  called  a  rocker. 

Cupriferous — Copper-bearing. 

Decrepitate — Crackling  when  -hot. 

Development — Work  done  in  opening  a  mine. 

Dip — The  inclination  of  a  vein  at  right  angles  to  its 
length. 

Dolly — A  primitive  stamp-mill. 

Drift — A  horizontal  gallery  in  a  mine;  or  the  rub- 
bish left  by  the  last  ice  age. 

Drifting — Driving  a  tunnel. 

Dump — A  heap  of  vein  stuff,  etc. 

Exploitation — The  actual  mining  following  explor- 
ation. 

Fathom — Six  feet. 

Fault — A  break  in  a  vein  or  bed. 

Float-gold — Fine  grains  that  do  not  sink  in  the 
water. 

Float — Veinstone  or  ore  by  which  a  vein  is  traced. 

Flume — Wooden  troughs  carrying  water. 

Flux — Material  added  to  help  fusion. 

Foliated — In  thin  layers. 


182  ABC   OF    MINING. 

Gangue — Veinstone. 

Gouge — A  selvage  of  clay  between  vein  and  country 
rock. 

Grade — The  inclination  of  a  ditch,  etc. 

Grating — Perforated  iron  sheet,  or  bars  with  spaces. 

Gravel — Broken  down,  rounded  rock  fragments. 

Ground  Sluice — A  gutter-  in  which  gold  is  washed. 

Iridescent — Showing  the  hues  of  the  rainbow. 

Litharge — Proto  oxide  of  lead. 

Long  Tom — A  machine  for  saving  alluvial  gold. 

Marl — Clay  containing  lime. 

Miner's  Inch — An  arbitrary  measure  of  water  regu- 
lated by  local  custom. 

Mundic — Iron  pyrites. 

Open  Cut — A  surface  working. 

Outcrop — That  part  of  a  vein  showing  on  the 
surface. 

Oxidation — A  chemical  union  with  oxygen. 

Oxide — Combination  of  a  metal  with  oxygen. 

Panning — Washing  gravel,  or  crushed  rock,  in  a 
gold-miner's  pan  to  detect  gold,  etc. 

Peroxide — The  oxide  of  any  substance  that  is  rich- 
est in  oxygen. 

Placer — A  deposit  of  valuable  metal  in  gravjel. 

Plat — A  map  from  an  original  survey. 

Plumbago — Graphite  or  black  lead. 

Precipitate — Matter  separated  from  a  solution. 

Pulp — Pulverized  ore  mixed  with  water. 

Quarry — An  open  working. 

Quartz — Silica. 

Quartzose — Containing  a  large  proportion  of  quartz. 


GLOSSARY.  183 

Reduce — To  turn  ore  into  metal  by  taking  away 
oxygen. 

Riffle — A  groove  or  strip  to  catch  gold  and  mercury 
in  a  sluice. 

Roasting — Heating  in  contact  with  air. 

Shaft — A  pit  giving  access  to  a  vein  or  working. 

Stratum — Bed  or  layer. 

Striated — Marked  with  parallel  workings. 

Strip — To  remove  overlying  material  from  a  vein. 

Sulphate- — A  salt  containing  sulphuric  acid. 

Sulphide — A  combination  of  sulphur  and  a  metal. 

Sulphurets — When  the  miner  employs  this  term  he 
usually  means  pyrites. 

Tailings — The  refuse  matter  after  ore  has  been 
crushed. 

Throw — The  movements  of  vein  caused  by  a  fault; 
it  may  be  up  or  down. 

Translucent — If  light  passes  through  a  mineral,  it 
is  translucent;  if  you  can  see  the  details  of  an  object 
through  it,  it  is  transparent. 

Underlie — The  same  thing  as  dip. 
.   Unstratified — Without  stratification  or  bedding. 

Wash  Dirt — Auriferous  gravel  or  clay. 

Whim — A  machine  for  hoisting  by  a  revolving 
drum. 

Winze — An  interior  shaft  connecting  the  levels. 

Zinc — White  oxide  of  zinc. 


This  book  U  DUE  on  the  last 
date  Mmped  below. 


MAY  241963 

MAR  31 
3?z27?'* 


LOS  ANGBLKS 


UCLA-Geology/Geophysics  Library 

TN270B733 


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